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These AP 9th Class Physical Science Important Questions 2nd Lesson Laws of Motion will help students prepare well for the exams.

AP State Syllabus 9th Class Physical Science 2nd Lesson Important Questions and Answers Laws of Motion

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Calculate the momentum of a fast moving ball with a velocity 2.2 m/s of mass 6 kg.
Answer:
mass (m) = 6 kg
velocity (v) = 2.2 m/s
momentum = mv = 6 × 2.2 = 13.2 kg.m.s^-1
The momentum of a fast moving ball is 13.2 kg ms^-1.

Question 2.
What is Newton’s first law of motion?
Answer:
Every object will remains at rest or in a state of uniform motion, unless compelled to change its state by the action of a net force.

Question 3.
From a fixed height, two eggs are dropped such that one falls on a concrete floor and the other on a cushioned pillow. The egg falling on the concrete floor breaks and the one falling on the pillow does not break. Explain why in terms of momentum.
Answer:

• The change of momentum of an egg takes place in shorter time in case of concrete surface.
• The change of momentum of the egg takes place in longer time in case of cushioned pillow.
• Hence, egg does not break on cushioned pillow.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
A vehicle of mass 300 kg travels at a velocity of 90 km/h. Find its momentum.
Answer:
Mass of the vehicle (m) = 300 kg
Velocity of the vehicle (v) = 90 km/h = 90 × \(\frac{5}{18}\) m/s = 25 m/s
Momentum = mv = 300 × 25 = 7500 kg.m.s^-1

Question 2.
“With our day to day experience, we must exert some force on an object to keep it moving”.
i) By which law, you can support the above lines?
ii) Which act on the body ? Either force or net force?
Answer:
i) Newtons first law of motion.
ii) Net force. The position of object is changed due to net force only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Fill the following table.

Answer:

Question 2.
What is impulse? Derive the formula for impulse.
Answer:
Impulse :
The change of momentum of an object is called impulse.
Formulae for impulse ⇒ ∆p = F_net∆t.

Derivation :
We can express the second law of motion as

From the above equation we know that the product of net force and interaction time is called impulse of net force (∆p).

Question 3.
State and prove the law of conservation of linear momentum.
Answer:
Law of conservation of momentum : Law of conservation of momentum states, in the absence of a net external force on the system, the momentum of the system remains unchanged.
Explanation :

• Let two marbles with masses nij and m2 travel with different velocities ut and u2 in the same direction along a straight line.
• If u₁ > u₂, they collide each other and the collision lasts for time’t’.
• During collision, each marble exerts force on other marble. [F₁₂ and F₂₁]
• Let v₁ and v₂ be the velocities of the marbles after collision.

Now look at the table.

• The total momentum before collision is equal to total momentum after collision.
• Hence, the total momentum remains unchanged before and after collision.

Question 4.
a) Name the ‘machine’ use to prove Newton’s laws of motion. Draw a neat diagram of it.
(OR)
The masses ‘m ‘ and ‘m2’ are attached to a string and roll over a pully, which is attached to a rigid support. Identify the machine and draw the neat diagram of it.
Answer:
a) Atwood machine.
Answer:

b) Draw FBD of both, masses on it.
Answer:

9th Class Physical Science 2nd Lesson Laws of Motion 1 Mark Important Questions and Answers

Question 1.
Newton’s first law of motion is also called
Answer:
Law of inertia.

Question 2.
State Newton’s second law of motion.
Answer:
The rate of change of momentum of a body directly proportional to the net force acting on it and it takes place in the direction of net force.

Question 3.
What is inertia?
Answer:
The natural tendency of objects to resist a change in their state of rest or of uniform motion is called inertia.

Question 4.
What is momentum?
Answer:
Linear momentum of a body is the product of its mass and velocity.
Momentum (p) = mass (m) × velocity (v)

Question 5.
State Newton’s third law of motion.
Answer:
When an object exerts a force on the other object, the second object exerts a force on the first one with equal magnitude and in opposite direction.

Question 6.
Write the law of conservation of momentum.
ANswer:
The law of conservation of momentum states that in the absence of net external force on the system, the momentum of the system remains unchanged.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Question 7.
What is an impulse?
Answer:
The product of net force and interaction time of a system is called impulse of net force.
Impulse ∆p = F_net. ∆t.

Question 8.
What is the Aristotle’s conclusion about the natural state of an object?
Answer:
Aristotle concluded that the natural state of an earthly object is to be at rest. Hence the object at rest requires no explanation as any moving object naturally comes to rest.

Question 9.
What is the Galileo’s conclusion on the motion of an object?
Answer:
Galileo gave birth to modern science by stating that an object in motion will remain in same motion as long as no external force is applied on it.

Question 10.
What is the effect of mass on inertia?
Answer:
As mass increases, inertia increases.
Mass is a property of an object that specifies how much inertia the object has.

Question 11.
Who proposed laws of motion?
Answer:
Sir Isaac Newton proposed the laws of motion.

Question 12.
Give two daily life examples where you experience inertia.
Answer:

• When the bus which is at rest begins to move suddenly, the person standing in the bus falls backward.
• When you are travelling in a bus the sudden stop of the bus makes you fall forward.

Question 13.
If action is always equal to the reaction, explain how a horse can pull a cart.
Answer:
Horse and cart constitutes a single system. So they cannot form action-reaction pair. Therefore, horse can pull the cart.

9th Class Physical Science 2nd Lesson Laws of Motion 2 Marks Important Questions and Answers

Question 1.
What is momentum? What are its units in S.I. system?
Answer:
Momentum (p) of a body is defined as the product of its mass (m) and velocity (v).
Momentum (p) = mass (m) × velocity (v)
p = mv
S.I. units of momentum are kg. m /sec (or) N – sec.

Question 2.
A mass of 0.5 kg has been suspended to a roof as shown in the figure. What is the force exerted by the rope on the object?

Answer:
The forces acting on the object of mass 0.5 kg are
i) gravitational force (downward) = 0.5 x 9.8 = 4.9 N
ii) Tension in the string T (upward).
The object is at rest. Hence the two forces are equal.
∴ The force exerted by the string on the object is 4.9 N (upwards).

Question 3.
Write few incidents if there were no friction.
(OR)
What happens when there were no friction in this world?
Answer:
If there were no friction,

1. we could not be able to walk on ground.
2. we would not be able to stop a fast moving car.
3. any object could not be able to stay on the ground.

Question 4.
What are the factors influencing acceleration? Explain.
Answer:
Factors influencing acceleration are force and mass.
Force :
As the net force increases, the acceleration increases when mass remains constant.

Mass :
When force is constant, as the mass increases, the acceleration decreases.

Question 5.
Why does a fielder catch a fast moving cricket ball by pulling back his arms while catching it?
(OR)
Why does a cricketer move his hands backwards while catching a fast moving cricket ball?
Answer:

• When he pulls back his arms he experiences a smaller force for a longer time.
• The ball stops only when your arms stop.
• This is to avoid a large impulse.
• If he doesn’t pull his arms back, the ball will hurt him.
• This is due to a larger force for a smaller time.

Question 6.
What is the state of an object when no net force is acting on an object?
Answer:
If the net force acting on an object is zero, the object which is at rest remains at rest or if the object is already moving with a certain velocity it continue to move with same velocity.

Question 7.
Which of the following has more inertia?
a) A rubber ball and a stone of the same size.
b) A bicycle and a train.
c) A five rupees coin and a one-rupee coin.
Answer:
As the mass of the object increases the inertia of the object increases.
a) Stone has more mass than rubber ball. So stone has more inertia.
b) Train has more inertia.
c) 5 rupee coin has more inertia.

Question 8.
Explain why some of the leaves may get detached from a tree, if we vigorously shake its branch?
Answer:
The leaves are at the state of rest. When the tree is vigorously shaken the state of rest is disturbed. So the leaves are detached from the tree due to inertia of rest.

Question 9.
Which would require a greater force – accelerating a 2 kg mass at 5 ms^-2 or a 4 kg mass at 2 ms^-2?
Answer:
Force F = ma
Here we have m₁ = 2kg, a₁ = 5 ms^-2 and m₂ = 4 kg, a₂ = 2ms^-2.
Thus F₁ = m₁a₁
Thus accelerating a 2 kg mass at 5 ms^-2 would require a greater force.

Question 10.
A motor car is moving with a velocity of 108 km/h and it takes 4s to stop after the brakes are applied. Calculate the force exerted by the brakes on the motor car if its mass along with the passengers is 1000 Kg.
Answer:

Question 11.
Explain why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
AnswerL
It is difficult for a fireman to hold a hose which ejects large amounts of water at a high velocity because due to high velocity of water the hose moves backward directiondue to Newton’s third law.

Question 12.
From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 ms^-1. Calculate the initial recoil velocity of the rifle.
Answer:
Mass of rifle m₁ = 4 kg
Mass of bullet m₂ = 50 g = \(\frac{50}{1000}\) = 0.05 kg
Initial velocity of rifle u₁ = 0
Initial velocity of bullet u₂ = 0
Final velocity of rifle (recoil velocity) v₁ = v
Final velocity of bullet v₂ = 35 ms^-1
According to law of conservation of momentum
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.
4(0) + 0.05 (0) = 4v + 0.05 × 35
4v = – 1.75
v = – 0.44 m/s

Question 13.
An automobile vehicle has a mass of 1500 kg. What must the force between the vehicle and road if the vehicle is to be stopped with a negative acceleration of 1.7 ms^-2?
Answer:
m = 1500 kg ;
a = – 1.7 ms^-2
F = ma = 1500 ×- 1.7 = -2550 N
Negative sign indicates that it is a retarding force.

Question 14.
What happens to a person standing in a bus when the bus which is at rest begins to move suddenly?
(OR)
Explain static inertia with an example.
Answer:

• The property of an object at rest will try to remain at rest is called “static inertia”.
• For example, when the bus which is at rest begins to move suddenly, the person standing in the bus falls backward because of static inertia of the body.
• Bus pulls the legs forward while body is in the rest position (static inertia).

Question 15.
Observe the given figure.
a) What happens to the coin, when we pull the paper with a jerk of force?
b) Why?
Answer:

1. The coin falls inside the glass.
2. This is due to static inertia of the coin.
3. This means coin in the state of ‘rest’ before and after pulling the paper. It falls down due to gravity only.

9th Class Physical Science 2nd Lesson Laws of Motion 4 Marks Important Questions and Answers

Question 1.
Give some examples for Newton’s third law of motion from your day-to-day observations.
Answer:
1) Flying of birds :
a) When birds fly, they push the air downward with their wings.
b) The air pushes back the bird in opposite upward direction.
c) These two forces are equal in magnitude and opposite in direction. Hence the bird can fly.

2) Swimming of fish :
a) When a fish swims in water, it pushes back the water.
b) The water pushes the fish with equal but in opposite direction.
c) Hence the fish moves forward.

3) Launching of a rocket:
a) A rocket accelerates by expelling gas at high velocity.
b) The reaction force of the gas on the rocket accelerates the rocket in a direction opposite to the expelled gases.

Question 2.
Derive F = ma.
Answer:
1) Newton’s second law of motion states that the rate of change of momentum of an object is proportional to the net force applied on the object in the direction of net force.

Question 3.
How did Galileo differ the statement of Aristotle ‘The natural state of an earthy object is to be at rest?
(OR)
Write the great experiments of Galileo on inclined planes.
(OR)
How do you appreciate Galileo, the father of modern science?
Answer:

• Galileo came up with two ingenious thought experiments.
• He did his experiments on inclined planes with smooth surfaces.
• He observed that the smoother the surface the farther the ball travelled.
• He extended this ajgument and concluded that if the surface was perfectly smooth, the ball will travel indefinitely until encountered by another object.

• As shown in the figure 1 (a) he observed that when a marble rolls down a slope it picks up speed due to the force of gravity of the earth.
• As shown in the figure 1(b) when the object rolls up an inclined plane, its speed decreases.
• Now let us assume that a marble is moving on a level surface as shown in the figure 1(C), it has no reason to speed up or slow down.
• So, it will continue to move with constant velocity.
• By this experiment, Galileo came to a conclusion which was in contrast to Aristotle’s belief that the state of an earthy object is to be at rest.

Question 4.
Explain Newton’s third Law of motion with an activity.
(OR)
Take two spring balances of equal calibrations. Connect the two spring balances and pull them in opposite direction. Does they show different readings? Why?
Answer:
Newton’s third law of motion : When an object exerts a force on an other object, the second object also exerts a force on the first one which is equal in magnitude but opposite in direction.

Activity:

1. Let us take two spring balances of equal calibrations.
2. Connect the two springs balances as shown in the figure.
3. Pull the balances in opposite direction.
4. Observation : Spring balances shows same readings.
5. Here, one spring balance shows reading of ‘action’ force, and other spring balance shows reading of ‘reaction’ force.
6. Forces are equal, direction are opposite.
7. This shows Newton’s third law of motion.

Question 5.
Take two marbles of m₁, m₂ mass respectively. Make a collision in one second with marbles using u₁, u₂ initial velocities respectively. Take the final velocities as v₁, v₂ You observed the following in the experiment.
m₁ = 10 kg u₁ = 5 m/s v₁ = 15 m/s
m₂ = 100 kg u₂ = 2 m/s -v₂ = 1 m/s
t = 1 sec
Fill the table with suitable answers and write the conclusion from it.

Answer:

Conclusion :

1. The table momentum is unchanged before and after collision.
2. We can say that the momentum is conserved.

Question 6.
How do you appreciate ‘Laws of motion’.
(OR)
How do you appreciate Newton, the great scientist.
Answer:

1. Built upon ideas primarily developed by Aristotle and Galileo, Sir Isaac Newton proposed his three fundamental Laws.
2. These Laws explain the connection between force and a change in motion.
3. These Laws are popularly known as Newton’s Law of motion.
4. Newton’s first law of motion : A body continuous its state of rest or of uniform motion unless a net force acts on it.
5. This law is very useful to study about inertia, mass, weight of an object.
6. This law is used to prepare cranes, machines, vehicles, etc.
7. Newton’s second Law of motion : The rate of change of memontum of a body is directly proportional to the net force acting on it and it takes place in the direction of net force.
8. This law is useful to find the attraction between two objects.
9. It is very useful to study the behaviour of substances like velocity, acceleration, force, momentum, etc.
10. Newton third law of motion : If an object exerts a force on an other object, the second object also exerts a force on the first one which is equal magnitude but opposite in direction.
11. This law is used to prepare rockets.
12. In this way Newtons Law’s are very useful in the fields of automobiles space centres and various industries.
13. In this way Newton laws changed the life of human beings.
14. So, I am appreciating the laws of motion and Newton for his great service to us.

Question 7.
Write suitable law and concept to the given situation or vice versa in the given table.

Answer:
A = Newton’s first law of motion
B = Static inertia
C = Newton’s third law of motion
D = Force of action = force of reaction
E = Newton’s second law of motion
F = Less impulse of net force
G = Newton’s third law of motion
H = Force of action = force of reaction
I = Fish swims in water
J = Force of action = force of reaction
K = Dropping egg on a cushion
L = Object thrown in universe (No external forces acts)
M = Newton’s first Law of motion
N = Bullet hurts
O = Newton’s second law of motion
P = Less impulse of net force
Q = Newton’s Second law of motion
R = Less momentum

These AP 9th Class Biology Important Questions 11th Lesson Bio Geo Chemical Cycles will help students prepare well for the exams.

AP State Syllabus 9th Class Biology 11th Lesson Important Questions and Answers Bio Geo Chemical Cycles

9th Class Biology 11th Lesson Bio Geo Chemical Cycles 1 Mark Important Questions and Answers

Question 1.
What are biogeochemical cycles?
Answer:
The cycles that involve the flow of nutrients in on earth from environment to organisms and back through certain pathways are known as biogeochemical cycles.

Question 2.
Write briefly about assimilation.
Answer:
Nitrogen compounds mainly as nitrates or ammonium ions (NH₄⁺) are taken up from soils by plants which are then used in the formation of plant proteins and as animals eat these plants, animal proteins are synthesised.

Question 3.
What is bio-geochemical cycle?
Answer:
A constant interaction between biotic and abiotic components of the biosphere makes a system and this flow of components form a cycle is called bio-geochemical cycle.

Question 4.
What is the percentage of nitrogen and oxygen in the air?
Answer:
Nitrogen – 78%
Oxygen-21%

Question 5.
Name few green house gases.
Answer:
Methane (CH₄), Carbondioxide (CO₂), and Carbon monoxide(CO).

Question 6.
What is denitrification?
Answer:
Conversion of nitrates into free Nitrogen is called denitrification.
Nitrates → Nitrogen(N₂)

Question 7.
What is nitrification?
Answer:
Conversion of free nitrogen present in the atmosphere into compounds of nitrogen is called nitrification.

Question 8.
Name the three processes by which oxygen is lost from the atmosphere.
Answer:
By combustion, respiration, and formation of oxides of nitrogen are the main processes by which oxygen is lost.

Question 9.
Why are root nodules useful for plants?
Answer:
In root nodules, nitrogen fixing bacteria Rhizobium’ is present which fixes the atmospheric nitrogen and make it available to the plant for its growth.

Question 10.
What is acid rain?
Answer:
The gases released due to combustion of fossil fuels are SO₂, NO₂, CO₂. These gases remain suspended in the air. When it rains, the rain water mixes with these gases to form sulphuric acid, nitrous acid, carbonic acid and comes down on the surface of the earth in the form of acid rain.

Question 11.
Give the names of few organisms that help in nitrogen fixation?
Answer:

• Rhizobium helps in the fixation of atmospheric Nitrogen into Ammonia.
• Nitrosomonas converts ammonia to Nitrates
• Nitrobactor converts nitrites into nitrates.

Question 12.
List any three activities which would lead to an increase in the carbon dioxide content of air.
Answer:

1. Burning of fossil fuels like coal, petroleum
2. Industrialisation
3. Deforestation

Question 13.
Which gas is added to the atmosphere by decay of organic matter?
Answer:
CO₂ (Carbondioxide)

Question 14.
List out three recently organized problems of environment.
Answer:
Ozone layer depletion, Green house effect, and Global warming.

Question 15.
What would happen if ail oxygen present in the environment is converted to ozone?
Answer:
Ozone is a poisonous gas and is present in a thin layer in the stratosphere. If all the oxygen is converted to ozone (O₃) the environment becomes poisonous and kills all living things.

Question 16.
Expand CFC’s.
Answer:
Chloro Fluoro Carbons

Question 17.
Expand B.O.D.
Answer:
Biological Oxygen Demand

Question 18.
What is the main concern of montreal protocol?
Answer:
To control the use of gases which have destructive effect on ozone layer.

Question 19.
Define Eutrophication.
Answer:
Increase growth of algae in lakes and ponds is called Eutrophication.

Question 20.
Which ’forms’ of nitrogen are taken up by plants from the soil?
Answer:
Nitrates and Ammonium ions.

Question 21.
What is the most abundant element in the atmosphere?
Answer:
Nitrogen.

Question 22.
What is called as ’Universal Solvent’?
Answer:
Water (H₂O).

Question 23.
How much percentage of water on the earth is present in the ocean?
Answer:
97%

Question 24.
What is the other name for water cycle?
Answer:
Hydrological cycle.

Question 25.
How many oxygen atoms are present in Ozone?
Answer:
Three – (O₃).

Question 26.
What is the chemical formula of ammonium ion?
Answer:
NH₄⁺

Question 27.
What are the affects of ‘Global warming’?
Answer:
1) Global warming affects the weather patterns on Earth and causes climatic change.
2) Climatic changes results in higher sea levels, more rainfall, severe droughts and floods.

9th Class Biology 11th Lesson Bio Geo Chemical Cycles 2 Marks Important Questions and Answers

Question 1.
What are the uses of water?
Answer:

• Water participates in many biochemical mechanisms, including photosynthesis, digestion, and cellular respiration.
• Living organisms drink water.
• Water is also used by terrestrial animals and plants for various life processes.
• Water provides hydrogen and oxygen that form integral part of basic organic compounds of life.

Question 2.
What is nitrification? What are the bacteria that participate in nitrification?
Answer:

• Nitrates can also be converted to ammonia by the denitrifying bacteria in the soil.
• The nitrifying bacteria may then use this ammonia to synthesize compounds for their own cell and eventually convert to proteins, nucleic acids, nitrites, and nitrates.
• Nitrites are produced mainly by nitrosomonas, while nitrates by nitrobacters that are also capable of utilizing nitrites and converting them to nitrates.
• Death of these organisms add the nitrogenous compounds to the soil.

Question 3.
What is ammonification? Under which conditions ammonification occurs?
Answer:

• Production of ammonia (NH₃) from nitrates and other nitrogenous compounds is called ammonification.
• Ammonification also occurs when plants and animals die, or when animals emit wastes, the nitrogen in the organic matter reenters the soil and water bodies where it is broken down by other organisms, known as decomposers.

Question 4.
What is denitrification? Explain the process of denitrification.
Answer:

• Denitrification is the conversion, principally by bacteria, of compounds of nitrogen in solid and aquatic systems to the gases, nitrogen (N₂) and nitrous oxide (N₂O) and eventual release of these into the atmosphere.
• Denitrification occurs primarily in wet soils where water makes it difficult for microorganisms to get oxygen.
• Under these conditions, certain organisms – known as denitrifying bacteria – will process nitrate to gain oxygen, leaving free nitrogen gas as by-product.

Question 5.
Explain briefly about green house effect.
Answer:

• Some gases present in the atmosphere such as carbon dioxide, carbon monoxide, methane, and water vapour trap heat from radiating back to the space.
• The natural green house gases act like a big blanket around the earth, keeping it warm and making life possible without which temperatures would have fallen to sub zero values.
• This phenomenon of naturally warming up is called ‘Green house effect’.

Question 6.
What are the uses of oxygen?
Answer:

• Oxygen helps in burning things.
• Oxygen is required for survival of living organisms.
• Respiration utilizes oxygen releasing carbon dioxide to atmospheric pool maintaining a balance in nature.
• Dissolved oxygen supports aquatic life.
• Oxygen is needed for the decomposition of organic waste.

Question 7.
What is biological oxygen demand? Explain briefly.
Answer:

• The content of biodegradable substances in water is expressed by a special index called “biological oxygen demand” (BOD).
• BOD represents the amount of oxygen needed by aerobic bacteria to decompose the waste.
• As the wastes get degraded and the dissolved oxygen is used up proportionately, the need or demand for oxygen increases i.e. the BOD increases.
• Thus BOD is a good indicator for amount of biodegradable waste.

Question 8.
What are the differences between oxygen and ozone?
Answer:

• Oxygen has two atoms and it is colorless and odourless.
• Ozone is a molecule containing three oxygen atoms. It is blue in colour and has a strong odour.

Question 9.
Complete the following flow chart.

Answer:

1. Ammonia
2. Nitrate
3. Denitrifying bacteria
4. Nitrosomonas
5. Nitrobactor

Question 10.
How is a balance maintained in the environment?
Answer:
The living or biotic components (plants and animals) and the non – living or physial components (air, water, soil, light and temperature) interact and affect each other resulting in the establishment of a complex and complete balance in the environment. There is a continuous cycle of nutrients among the biotic and abiotic components.

Question 11.
Write the two harmful effects of ozone hole.
Answer:

• Ozone hole allows harmful U.V radiation to reach the earth’s surface that may cause skin cancer, cataract, etc
• Ultraviolet rays also ionize the cells, change the gene structure in animals and plants.

Question 12.
What are the harmful effects of acid rain?
Answer:

• It makes the soil acidic.
• It damages the crops and plantations.
• It corrodes statues, monuments of marble buildings, etc…

Question 13.
What is the difference in fog and smog? Give two harmful effects of smog.
Answer:
The water vapour present in air when condenses due to very low temperature is called fog. The smoke released in the air due to burning of fuels mixes with the fog and forms smog.
Smoke + Fog = Smog
a) Smog reduces visibility
b) Smog creates respiratory diseases like asthma etc.

Question 14.
What is bad ozone and good ozone?
Answer:
Ozone when present in the earth’s surface is very poisonous gas hence called bad ozone. When ozone present in stratosphere is very protective in nature as it does not allow the harmful U.V radiation to enter the earth’s atmosphere and hence is called good ozone.

Question 15.
Consider that there is a mass mortality of Ashes in a pond. Guess, what may be the reason for that.
Answer:

• Addition of hot water to the fish tank may leads to their death.
• Addition of poisonous mercury compounds in water may leads to their death.
• Blockage of gills of fishes with any pollutant may be .a cause for their mass death.

Question 16.
Why is it said that nitrogen is important for us?
Answer:

• Nitrogen is the most abundant gas in our atmosphere (78%)
• Nitrogen is a part of many molecules essential to our life like proteins, nucleic acids, (DNA and RNA), and some vitamins.
• It is found in other biologically important compounds also such as alkaloids and urea.

9th Class Biology 11th Lesson Bio Geo Chemical Cycles 4 Marks Important Questions and Answers

Question 1.
Write about the expansion of water on earth.
Answer:

• Nearly 97% of all the water on the earth is in the oceans, and so only about 3% is freshwater.
• About 2% of this fresh water is permanently frozen in glaciers and at the polar ice caps.
• Thus only about 1% is available fresh water.
• Again about 1/4 of this 1% is present as underground water.
• Only about 0.009% of water on earth is in the rivers and lakes.
• Rest is present in the bodies of living organisms, as soil moisture, as humidity of atmosphere, etc.
• Water is the most essential, abundant substance in living things.
• The human body, for example, is composed of about 70% of water.

Question 2.
What is water cycle? Explain it briefly.
Answer:

• The whole process in which water evaporates and falls back on the surface of the earth as rain and other forms of precipitation including its flow from land into the sea/oceans via several routes like rivers, ground water channels, etc., is known as the water – cycle.
• All of the water that falls on the land does not immediately flow back into the sea.
• Some of it seeps into the soil and becomes part of the underground reservoir of fresh water.
• Some of this underground water finds its way to the surface through springs.
• We bring it to the surface for our use through wells or tube wells.
• Water is continuously exchanged between sea, land and atmosphere.

Question 3.
What is nitrogen fixation? How it occurs?
Answer:

• Atmospheric nitrogen occurs primarily in inert form (N₂) or non-reactive form that few organisms can use; therefore it must be converted into a compound (or) fixed form in a process called nitrogen fixation.
• Most atmospheric nitrogen is ‘fixed’ through biological processes.
• A number of bacteria and blue green algae are known to be able to fix atmospheric nitrogen into compounds in their own body.
• These may be symbiotic e.g.: Rhizobium or free living, e.g.: Nitrosomonas respectively.
• These organisms convert atmospheric nitrogen into the organic nitrogen for their own cells.
• In leguminous plants like pea, beans, etc., there is a symbiotic relationship of the nitrogen fixing bacteria with the plant, thus nitrogenous compounds are added to the soil after a leguminous crop is grown.
• Nitrogen can also be fixed as nitrates by lightning.

Question 4.
In which forms carbon found on earth?
Answer:

• Carbon is found in various forms on the earth.
• It occurs in the elemental form as say soot, diamond, and graphite.
• In the combined state, it is found as gases, carbon dioxide, and carbon monoxide in the atmosphere, as carbonate it is found in various salts and minerals.
• While all life – forms are composed of carbon containing molecules like proteins, carbohydrates, fats, nucleic acids, and vitamins.
• The endoskeletons and exoskeletons of various animals are also formed from carbonate salts.

Question 5.
What is Global warming? What are its effects?
Answer:

• Due to human activities, an excessive amounts of carbon dioxide and other green house gases has been emitted to the environment.
• As a result, more heat gets trapped.
• This causes the temperature of the earth to rise, which results in global warming.
• Global warming is the recorded increase in the average temperatures of the earth’s atmosphere and oceans.
• Global warming affects the weather patterns on earth and cause climate change.
• Climate change results in higher sea levels, more rainfall, and severe droughts and floods.

Question 6.
Describe carbon cycle briefly.
Answer:

• Carbondioxide is used by plants for photosynthesis.
• During this process, CO₂ is converted to glucose.
• Some amount of this glucose is used for respiration by plant.
• Rest of it converted to other carbohydrates and fats stored in various parts of plants.
• When animals eat plants these carbon containing compounds are taken up by the animals and digested and absorbed.
• These are used by animals for respiration.
• Thus carbon in carbon dioxides in atmos-phere finds its way into animals.
• Metabolic degradation of these compounds especially during respiration releases the CO₂ into air.
• Decomposition of dead bodies of animals and plants by bacteria also releases CO₂ into air.
• Thus the CO₂ find its own way into the bodies of animals and plants and back to air.

Question 7.
Briefly describe oxygen cycle.
Answer:

 

• Oxygen dissolved in water is used for respiration by aquatic plants and animals,
• Terrestrial animals use oxygen present in air for their respiration.
• The by-products of respiration, CO₂ and water are released into air.
• These two are taken up by plants and are used for photosynthesis.
• The by-product of photosynthesis is oxygen, which is released into air.
• CO₂ is also formed when fuels are burnt.
• There is fine balance between these processes so that the total amount of oxygen present in air remains constant.
• All these processes together represent oxygen cycle.

9th Class Biology 11th Lesson Bio Geo Chemical Cycles Important Questions and Answers

Question 1.
Asa responsible citizen what measures you would follow to reduce global warming at your school or village level?
Answer:

• Planting trees in open fields and wastelands.
• Minimising the usage of motorcycles and start using cycles which are eco-friendly.
• Stop burning of firewood, which release the green house gases start using LPG cylinders for cooking.

Question 2.
What is nitrification? Explain how it occurs.
Answer:

1. The denitrifying bacteria present in the soil convert the nitrates into Ammonia.
2. Nitrifying bacteria utilises this ammonia and form proteins, nitrites, nitrates.
3. Nitrosomonas produce nitrites whereas nitrobactor produce nitrates.
4. Due to the death of microorganisms in the soil, the soil becomes nitrogen rich.

Question 3.
Write differences between nitrification and denitrification.
Answer:

Nitrification	Denitrification
1) The part of nitrogen cycle, whereammonium (NH4+) is converted into Nitrate (NO3–) is called nitrification.	1) This is the level where reduction of nitrate (NO3–) is made into Nitrogen (N2)
2) This involves nitrifying bacteria like Nitrobactor Nitrosomonas.	2) This involves denitrifying bacteria like 4 spirillum, lacto bacillus, pseudomonas thiobacillus.
3) Occurs slowly.	3) Occurs rapidly.
4) This requires aerobic condition.	4) This requires anaerobic condition.
5) The microbes involved in this process are autotrophs.	5) The microbes involved in this process are heterotrophs.
6) The end product is nitrate.	6) The end product is nitrogen.

Question 4.
Explain how human activities lead to global warmig.
Answer:

1. Deforestation
2. Burning of excess of fossil fuels in industries and automobiles.
3. Power genaration and utilization
4. Refrigerators, coolers, cell towers
5. Automobiles and cement roads etc.
6. Forest fires and burning of firewood.

Question 5.
Observe the following figure and answer the following questions.

a) What is green house effect?
b) Apart from rest of the world which country contributes more for it?
c) What are CFCs? Give some examples.
d) Suggest some preventive measures to reduce it.
Answer:
a) The phenomenon of naturally warming up by CO₂ and water vapour is called “Green house effect”.
b) USA
c) Fully or partly halogenated paraffin hydro carbons that contain only carbon (C), hydrogen (H) chlorine (Cl) and fluorine (F) which are volatile are called chloro fluorine.
Ex : Freon – 12, R – 410A, R -134

d) i) Stop deforestation
ii) Restrict the usage of fossil fuels
iii) Introducing eco friendly fuels like CNG.
iv) Introducing alternative energy resources like solar energy, wind power etc.

These AP 9th Class Social Studies Important Questions 21st Lesson Human Rights and Fundamental Rights will help students prepare well for the exams.

AP State Syllabus 9th Class Social 21st Lesson Important Questions and Answers Human Rights and Fundamental Rights

9th Class Social 21st Lesson Human Rights and Fundamental Rights 1 Mark Important Questions and Answers

Question 1.
What is a writ?
(OR)
What do you understand about ‘writt1? (SA-II : 2017-18)
Answer:

• Writ is an authority given to the court to issue directions to the government to protect and enforce any constitutional right.
• It is an inherent power given to the court.
• The court can “Suo motu” (on its own motion) take congnizance of a violation of fundamental rights.

Question 2.
Write any two slogans about abolition of child labour. (SA-II : 2017-18)
Answer:
1. Child is your heart not born to push your cart.
2. Children are the future heroes, they need to learn before they can work.

9th Class Social 21st Lesson Human Rights and Fundamental Rights 2 Marks Important Questions and Answers

Question 1.
Read the following situations. Which Fundamental Right is being violated in each case and how? (SA-II : 2018-19)
i. A director who makes a documentary film that criticizes the policies of the government is arrested and sent to prison.
ii. A ten years old boy is not allotted to go to school and is forced to work in a firecracker factory.
Answer:
i) In first case Right to freedom of speech and expression is violated. Everyone has a right to express their opinion on the administration of govt. But some limitations are there.
ii) In the second case, Right against exploitation is violated.
The Constitution says “no child below the age of 14 shall be employed engaged in any other hazardous employment.

Question 2.
Read the following concepts and write under the table with relevant fundamental right. (SA-II : 2017-18)

• Prohibition of employment for children in factories.
• All minorities shall have the right to establish and administer educational institutions of their choice.
• Abolition of titles.
• Right to life.

Answer:

9th Class Social 21st Lesson Human Rights and Fundamental Rights Important Questions and Answers

Question 1.
Write a short note about UDHR.
Answer:

• A group of people from 9 countries around the world formed by UNO drafted a list of 30 articles.
• This became the Universal Declaration of Human Rights.
• It was passed by the UN General Assembly in 1948.

Question 2.
What are the functions of NHRC?
Answer:

• NHRC is vested with the authority to make an inquiry, Suo motu or on a petition presented to it by a victim.
• It works for protecting human rights.
• It intervenes in any case involving human rights in the court or outside the court.

Question 3.
What are our fundamental duties?
Answer:
The fundamental duties to be discharged by the citizens were not there in our Constitution earlier. They were included through 42nd amendment. They are :

1. Respecting the constitution, National Flag and National Anthem.
2. Cherishing the noble ideals of the freedom struggle.
3. Defending the country and rendering national service when called for.
4. Upholding and protecting the sovereignty, unity and integrity of India.
5. Promoting harmony and the spirit of common brotherhood amongst all the people of India and renouncing any practice derogatory to the dignity of women.
6. Preserving the rich heritage of the Nation’s composite culture.
7. Protecting and improving the natural environment including forests, lakes, rivers and wild life and having compassion for living creatures.
8. Developing scientific temper, humanism and spirit of inquiry or reform.
9. Safeguarding public property and abjuring violence.
10. Striving for the excellence in all individual and collective activities.

Question 4.
What are the differences between the fundamental rights and fundamental duties?
Answer:
1) Fundamental rights :
a) Fundamental rights are definite.
b) No one can deprive us of these rights.
c) Even Government cannot ignore them.
d) These rights are safeguarded through court of law.

2) Fundamental duties :
a) No one can force us to abide to them.
b) The discharge of fundamental duties is left to our discretion.
c) No court can force us to discharge these duties.

Question 5.
Read the passage and answer the following questions.
Human Rights Commission :

The United Nations has been working to protect the basic human rights of people and in this effort they have encouraged their member nations to do the same. In 1993,the Government of India passed an act of legislature to protect human rights. A commission for human rights was set up under this law called the National Human Rights Commission (NHRC). The commission has been given powers of a civil court extendable to the entire country. The Government has also established other institutions to monitor and inquire into situations in which rights are violated. Thus we have different institutions such as the National Commission for Women, National Commission for Protection of Child Rights, National Minority Commission and State Human Rights Commissions.
i) When did the Government of India pass an act of legislature to protect human rights?
Answer:
In 1993 the Government of India passed a legislature.

ii) Expand NHRC.
Answer:
NHRC means National Human Rights Commission.

iii) What are the institutions that work on Human Rights?
Answer:
1) National Human Rights Commission.
2) National Commission for Women.
3) National Minority Commission.
4) State Human Rights Commission.

iv) What does the above Logo stand for?
Answer:
It is the logo of Human Rights designed by the United Nations Organization.

v) Which organization is behind the establishment of Human Rights Commission?
Answer:
The UNO is instrumental in establishing the Human Rights Commission.

Question 6.
Gather certain information about violation of fundamental rights and how the court protected them.
Answer:
I.

1. One factory was emitting dangerous gases and health of the people was effected.
2. A public interest litigation is filed in the court.
3. The factory was forced to close down. As it is against the fundamental right of Right to life.

II.

1. One child was working as a domestic servant in a family.
2. The family members went on a tour for two days.
3. The child (servant) was kept in the house and the door was locked from outside.
4. The neighbours recognized it. Given a complaint to the police.
5. The police broke open the doors and a case was filed against the head of the family.

Question 7.
Which of the following rights is available under the Indian Constitution?
a) Right to work
b) Right to adequate livelihood
c) Right to protect one’s culture
d) Right to privacy
Answer:
c) Right to protect one’s culture

These AP 9th Class Biology Important Questions 2nd Lesson Plant Tissues will help students prepare well for the exams.

AP State Syllabus 9th Class Biology 1st Lesson Important Questions and Answers Plant Tissues

9th Class Biology 2nd Lesson Plant Tissues 1 Mark Important Questions and Answers

Question 1.
What are the functions of stomata?
Answer:

• These are essential for exchange of gases with the atmosphere.
• During transpiration loss of water takes place in the form of water vapour through stomata.

Question 2.
How many types of elements together make up the xylem tissue?
Answer:
Xylem tissue consists of four types of elements. They are trachieds, vessels, xylem parenchyma and xylem fibres.

Question 3.
What are the constituents of phloem?
Answer:
Phloem is made up of five types of elements. They are sieve tubes, sieve cells, companion cells, phloem fibres and the phloem parenchyma.

Question 4.
How can the plants perform all the life processes?
Answer:
Different parts of the plant having specific tissues perform specific function.

Question 5.
Meristematic tissue present at the tips of root and shoot is called as?
Answer:
Apical meristem.

Question 6.
Which portion of the plant is responsible for transport of water, minerals and food materials?
Answer:
Stele

Question 7.
What is the other name for stomata?
Answer:
Airpores

Question 8.
Name the cells which divide continuously.
Answer:
Meristematic cells.

Question 9.
Which tissues makes up the husk of coconut?
Answer:
The husk of coconut is made of sclerenchyma tissue.

Question 10.
What is the role of epidermis in plants?
Answer:
Cells of epidermis form a continuous layer without intercellular spaces. It protects all the parts of the plants.

Question 11.
What are guard cells? What is their function?
Answer:
Each stomata is bound by a pair of specialised epidermal cells called guard cells. They control the opening and closing of the stomata.

Question 12.
How many types of elements together make up the xylem tissue? Name them.
Answer:
Xylem is made up of vessels, trachieds, xylem fibres and xylem parenchyma.

Question 13.
What are the constituents of Phloem?
Answer:
Phloem constitutes the sieve tubes, companion cells, phloem parenchyma and phloem fibres.

Question 14.
What is a vascular tissue?
Answer:
Any tissue which contain vessels through which fluids are passed is called a vascular tissue.

Question 15.
Identify the given tissues.
Answer:

Question 16.
Name the branch of science that deals with the study of tissues.
Answer:
Histology

Question 17.
Name the scientist who coined the term ‘Parenchyma’.
Answer:
Nehamiah Grew

Question 18.
Name the plants that are possessed with Arenchyma.
Answer:
Water plants like Pistia, Eichornia.

Question 19.
Name the tissue that protects the trees from strong winds.
Answer:
Collenchyma gives flexibility and tensile strengh to the branches of the trees and protect them from strong winds and make them to bend. So, the branches won’t break up when they are exposed to the strong winds.

Question 20.
Where do you find sieve cells? What is their function?
Answer:
Sieve cells found in phloem helps in the transportation of materials.

Question 21.
What are companion cells and state their function?
Answer:
Companion cells are the parts of phloem aiding in transport of materials.

Question 22.
Where do you find vessels? Write their function.
Answer:
Vessels are found in xylem helps in conduction of nutrients. They also give mechanical support to the plant.

Question 23.
Name the tissue that is present in root tips.
Answer:
Meristematic tissue.

Question 24.
What is meant by differentiation?
Answer:
The process of taking up a permanent shape, size and function is called differentiation.

Question 25.
What happens to the plant if the vascular bundles are destroyed?
Answer:
The transportation of water, nutrients and food in that plant is totally stopped. Hence, the plant will die.

Question 26.
Name the tissue, that brings about overall growth and repair in plants.
Answer:
Meristematic Tissue.

Question 27.
Name the tissue, that form the bulk of the plant body, helping in packing other tissues.
Answer:
Ground Tissue.

Question 28.
Name the parts of the plant that helps in reproduction.
Answer:
Flowers

9th Class Biology 2nd Lesson Plant Tissues 2 Marks Important Questions and Answers

Question 1.
Name the different elements of xylem. Collect information about the uses of the elements of xylem.
Answer:

• Xylem consists of trachieds, vessels, xylem parenchyma and xylem fibres.
• Trachieds and vessels are tubular structures. This allows them to transport water and minerals vertically.
• The parenchyma stores food and helps in the sideways conduction of water.
• Fibres are mainly supportive in function give mechanical support to vascular bundles.

Question 2.
What are the differences between the plant tissues and animal tissues?
Answer:

Plant Tissues	Animal Tissues
1. Most of the tissues are dead.	1. Most of the tissues are living.
2. Plants need less maintenance energy.	2. Animals need more maintenance energy.
3. Tissues organisation is to support fix habitat.	3. Tissues organisation help the organism for locomotion.

Question 3.
What are the differences between simple tissue and complex tissue?
Answer:

• Simple tissues are composed of one type of cells which are structurally and functionally similar.
  e.g. : Parenchyma, Collenchyma and Sclerenchyma.
• Complex tissues consists of more than one type of cells which perform a common function.
  e.g.: Xylem and phloem.

Question 4.
What are the characteristic features of cells in meristematic tissue?
Answer:
Cells in the meristematic tissue are

1. Small and having thin cell wall.
2. Living with prominent nucleus and abundant cytoplasm.
3. Compactly arranged without intercellular spaces.
4. Continuously dividing cells.

Question 5.
Differentiate between Parenchyma, Collenchyma and Sclerenchyma on the basis of their cell walls.
Answer:

Parenchyma	Collenchyma	Sclerenchyma
The cell walls are thin and made of cellulose.	The cell walls are thick due to cellulose and pectin formation in some places on the walls.	Due to lignin deposition cell walls are thick.

Question 6.
Complete the following flow chart.
Answer:

1. Parenchyma
2. Sclerenchyma
3. Collenchyma
4. Xylem
5. Phloem
6. Chlorenchyma
7. Arenchyma

Question 7.
Write down the arrangement of cells in the given table :
Answer:

Arrangement of the cells (Tissues)	Shoot tip	Root tip
1. At the tip	Apical meristems are present.	Meristems below the root cap are present.
2. At the lateral side	Lateral meristems are present.	Lateral meristems are present.
3. At the point of branching	Intercalary meristems are present.	Meristems are absent

Now answer the following questions.
1) Where do you find meristems in the root tip?
Answer:
Below the root cap.

2) Where do you find intercalary meristems in the shoot tip?
Answer:
At the point of branching

Question 8.
Draw a neat and labelled diagram of stomata.
Answer:

Question 9.
a) Identify the given structures.
b) State the role performed by the two structures.

Answer:
a) A is trachied
B) B is vessel
Both help in transporting water and minerals vertically.

Question 10.
Observe the diagram of location of meristematic tissue in plant body. Identify the types of meristematic tissue found in the labelled regions and write their functions.
Answer:

1. Apical meristems are found in the A region
2. Lateral meristems are found in the B region.
3. Apical meristem increases the length of the stem and the root.
4. Lateral meristem (cambium) increases the growth of the stem and root.

Question 11.
How does the cork act as protective tissue?
Answer:

• Cork has dead cells and compactly arranged without intercellular spaces.
• They have deposition of suberin on the walls that make them impervious to gases and water.

Question 12.
How do you appreciate the functions of vascular tissue in plants?
Answer:

• Vascular tissues carry water to a great heights in the plant body.
• It is upto nearly 200ft in Eucalyptus plants and upto nearly 330ft in the Redwood trees.
• It is an amazing factor of nature. I appreciate the functions of vascular tissue which carry water up to a greater heights.

Question 13.
Write a note on Arenchyma.
Answer:

• Air spaces are present in this type of Parenchyma.
• This type of Parenchyma is seen in plants which float on water, such plants are called hydrophytes.
  Ex : Pistia, Eichornia, Hydrilla.

9th Class Biology 2nd Lesson Plant Tissues 4 Marks Important Questions and Answers

Question 1.
Draw a flow chart for plant tissues.
Answer:

Question 2.
What are meristems? Write the types of meristems.
Answer:
1. Tissues that bring about overall growth and repair are called meristems.

2. Meristems are of three types.

1. Apical meristems
2. Intercalary meristems
3. Lateral meristems.

3. Meristems at the growing tip that bring about growth in length are apical meristems.
e.g. : Stem and Root tips.

4. Meristems present around the edges in a lateral manner and giving rise to growth in diameter or girth of the stem are called lateral meristems.

5. Meristems present at the branching takes place or a leaf or a flower stalk grows are known as intercalary meristems.

Question 3.
Describe the structure of parenchyma, collenchyma and sclerenchyma with the help of a diagram.
Answer:
1) Structure of Parenchyma :

1. The cells of parenchyma are soft thin walled and loosely packed.
2. The parenchyma which contains chloroplasts is chlorenchyma, parenchyma which contains air spaces is arenchyma and the parenchyma which stores food or water is storage tissue.

2) Structure of Collenchyma :

1. Collenchyma tissues have thicker walled longer cells.
2. They give mechanical support to plant.
3. Intercellular spaces are present.

3) Structure of Sclerenchyma :

1. In the sclerenchyma the cells are thick walled and compactly arranged withtiearly no spaces between them.
2. They give mechanical strength to the plant.

Question 4.
Draw the diagram showing different types of ground tissue in plants.
Answer:

Question 5.
Draw the diagram showing different cells of xylem and phloem.
Answer:

Question 6.
Draw and label the diagram of L.S. of shoot tip.
Answer:

Question 7.
If you want to know more about Xylem and phloem, what questions will you ask?
Answer:
I will ask the following questions to know more about xylem and phloem.

1. What is the economic importance of xylem and phloem?
2. What are the factors that are helpful to vascular tissue in conducting water?
3. How do plants get water in the higher mountains?
4. What is the commercial importance of bast fibres?

9th Class Biology 2nd Lesson Plant Tissues Important Questions and Answers

Question 1.
What will happen if stomata are absent in the leaves of the plant
Answer:

1. Gaseous exchange will not takes place in leaves.
2. Transpiration does not take place.

Question 2.
What are the different types of ground tissues in plants
Answer:

1. Parenchyma
2. Collenchyma
3. Sclerenchyma

Question 3.
Give reasons.
a) Xylem is a conductive tissue.
b) Adipose tissue acts as an insulator of heat.
c) Cardiac muscle works without rest.
d) Epidermis provides protection to plants.
Answer:
a) Xylem acts as conducting tissue as it transports water and minerals from the roots to the top of tree.

b) Fat in our body is stored in adipose tissue. It is found below the skin and between internal organs. They act as insulators.

c) i) The muscles present in the heart are responsible for pumping of blood.
ii) The cells are long, branched and have nuclei.
iii) Cardiac muscles have striations. Though they have striations, they are involuntary muscles.

d) i) Dermal tissue (Dermis) usually consists of a single layer of tissues showing variations in the types of cells on the basis of their functions and location.
ii) The dermal tissue protects the plants from loss of water, mechanical damage like breaking and cleaning of branches and invasion of parasites and disease causing organisms.

Question 4.
Read the following paragraph and answer the following questions :

The cells of the parenchyma are soft, thin walled and loosely packed. The parenchyma which contains chloroplast is called Chlorenchyma. The parenchyma which contains large air spaces are called Aerenchyma and which store water or food is called storage tissue. Collenchyma have thicker walls and longer when compared to Parenchyma. In the sclerenchyma the cells are thick walled and compactly arranged with nearly no spaces between them.

a) What does the paragraph denote?
b) What function does chlorenchyma perform and why?
c) In which plants do you find Aerenchyma abundantly and why?
d) Give some examples of plants where storage tissue is commonly seen.
Answer:
a) Ground tissue in plants.
b) Chlorenchyma has chloroplasts, which are capable of trapping solar energy. Hence, they perform photosynthesis.
c) Aerenchyma is found in water plants [Hydrophytes], Aerenchyma enables the water plant to float on water.
d) Potato, Carrot, Raddish.

Question 5.
a) Kshitija selected a plant and took out a thin section of its stem. She observed it under powerful compound microscope. Draw a diagram of what she observed and label it.
b) Add a note on Vascular bundle.
Answer:
a)

b)

1. Xylem and phloem are collectively called as Vascular bundle.
2. They are called as conducting tissue or vascular tissue.
3. Xylem is responsible for transportation of water and salts.
4. Phloem is responsible for transportation of food materials prepared by photosynthesis in other parts of the plants.

WorkBook Part

1. Take permanent slides of chlorenchyma, arenchyma, storage tissue in your labora-tory. Observe them under microscope and write their characters and differences.
2. Draw and label the diagram of the T.S. of stem.
3. How many basic types of tissues are there in plants? What are they?
4. Write the name of the following picture and write its parts.

These AP 9th Class Physical Science Important Questions 3rd Lesson Is Matter Pure? will help students prepare well for the exams.

AP State Syllabus 9th Class Physical Science 3rd Lesson Important Questions and Answers Is Matter Pure?

9th Class Physical Science 3rd Lesson Is Matter Pure? 1 Mark Important Questions and Answers

Question 1.
There is a mixture with sand and iron filings. Write an activity for the separation of iron filings from sand.
Answer:

1. Take mixture of sand and iron filing in a tub.
2. Take a magnet and move over the mixture.
3. Iron filings are separated by sticking to the magnet.

9th Class Physical Science 3rd Lesson Is Matter Pure? 2 Marks Important Questions and Answers

Question 1.
Frame two questions to understand “Homogeneous mixture”.
Answer:

• Can you see components in homogenous mixture?
• In which mixture components are uniformly distributed, heterogeneous or homogeneous?

Question 2.
How can you use milk to show Tyndall effect?
Answer:

1. Take milk in a glass.
2. Pass light through the milk.
3. Milk particles shine due to scattering of light.
4. This is the Tyndall effect.
5. Milk is a colloidal solution.

9th Class Physical Science 3rd Lesson Is Matter Pure? 4 Marks Important Questions and Answers

Question 1.
Draw the arrangement of apparatus of fractional distillation experiment. What is the advantage of using the fractionating column?
Answer:

1. Fractional distillation column contains glass beads.
2. These glass beads in fractional distillation column provide maximum possible surface area for the vapours to cool and condense repeatedly.

Question 2.
Draw and label the apparatus set up for the separation of a mixture by sublimation.
Answer:

Question 3.
Draw and label the apparatus set up for the separation of a mixture by evaporation.
Answer:

Question 4.
Explain how two miscible liquids can be separated if their boiling points are close to each other.
Answer:

To separate two or more miscible liquids when the difference in their boiling points is less than 25°C, fractional distillation process is used.

Aim :
To separate two miscible liquids (water and acetone) by fractional distillation.

Materials required :
Stand, distillation flask, thermometer, condenser, beaker, acetone and water, one holed rubber cork.

Procedure:

1. Take a mixture of acetone and water in a distillation flask.
2. Fix a thermometer as shown in the figure and clamp to the stand.
3. Attach condenser to the flask.
4. Keep a beaker to collect distillate at the end of condenser.
5. Heat the mixture slowly.
6. Observe the reading of thermometer.
7. The acetone (low boiling point) vapourises and condenses.
8. It can be collected from the condenser outlet.
9. Water remains in the distillation flask. ,

Question 5.
800 ml of solution contains 20 grams of solute. Calculate the concentration in terms of mass by volume percentage of the solution.
Answer:

Question 6.
a) Diagram shows one of the process of separation by mixtures. Based on the diagram answer the following questions.
i) Identify the process involved in the diagram.
Answer:
Sublimation.

ii) Is something missing in the diagram. If so what is that?
Answer:
Stove is missed for heating.

iii) If ‘B’ represent ammonium chloride, then what is ‘A’ represent?
Answer:
Mixture of ammonium chloride and salt.

iv) Give one more example for separation of mixture using above process?

Answer:
Camphor and salt.

Question 7.
Name the instrument used to separate immiscible liquids. Draw a neat diagram of it taking kerosene and water as immiscible liquids.
Answer:
The instrument used to separate immiscible liquids is separating funnel.

9th Class Physical Science 3rd Lesson Is Matter Pure? Important Questions and Answers

9th Class Physical Science 3rd Lesson Is Matter Pure? 1 Mark Important Questions and Answers

Question 1.
What is meant by ‘Pure substance’?
Answer:
In our day to day language, ‘pure’ means something with no adulteration. A substance is said to be pure i.e., homogeneous when the composition doesn’t change, no matter which part of the substance you take for examination.

Question 2.
What is a mixture?
Answer:
A mixture is generally made of two or more components that are not chemically combined.

Question 3.
What is a homogeneous mixture? Give examples.
In a homogeneous mixture the components of the mixture of uniformly distributed throughout it.
Ex : Lemonade, sugar solution, air, etc.

Question 4.
What is a heterogeneous mixture? Give examples.
Answer:
A heterogeneous mixture is a mixture made up of different substances or the same substance in different states which are not uniformly distributed in it.
Ex : Mixture of oil and water; water and naphthalene, etc.

Question 5.
What are the factors affecting rate of dissolving?
Answer:
The factors affecting rate of dissolving are
i) Temperature of solvent,
ii) Size of solute particles,
iii) Stirring of the solution.

Question 6.
When do you say that a solution is dilute solution?
Answer:
If the amount of solute present is little, the solution is said to be dilute.

Question 7.
What do you say that a solution is a concentrated solution?
Answer:
If the amount of solute present is more in a solution, then the solution is said to be a concentrated solution.

Question 8.
Define suspension.
Suspensions are the heterogeneous mixtures of a solid and a liquid in which the solids do not dissolve, like mixtures of soil and water.
Ex : Mixture of sand and water.

Question 9.
Define emulsion and give an example.
Answer:
Emulsion is a mixture consisting of two liquids that do not mix and settle into layers when they left undisturbed.
Ex : Mixture of oil and water.

Question 10.
What is a colloid?
Answer:
Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but big enough to scatter light.
Ex : Milk, Cheese, Ghee, etc.

Question 11.
What is Tyndall effect?
Answer:
Scattering of a beam of light is called Tyndall effect.

Question 12.
What technique do you use to separate the colours?
Answer:
The laboratory technique called chromatography is used for the separation of mixtures into its individual components like inks and dyes.

Question 13.
When do we use fractional distillation method for the separation of miscible liquids?
Answer:
To separate two or more miscible liquids when the difference in their boiling points is less than 25°C, fractional distillation process is used.

Question 14.
What is the definition given by Lavoisier for the ‘element’?
Answer:
According to Lavoisier, an element is a form of matter that cannot be broken down by chemical reactions into simpler substances.

Question 15.
What is the principle involved in separation of immiscible liquids using separation funnel?
Answer:
The underlying principle involved in separation of immiscible liquids using separating funnel is that the immiscible liquids separate out into layers depending on their densities.

Question 16.
What is the use of glass beads in the fractional distillation column?
Answer:
The glass beads in fractional distillation column provide maximum possible surface area for the vapours to cool and condense repeatedly.

Question 17.
How will you separate a mixture containing kerosene and petrol (difference in their boiling points is more then 25°C). Which are miscible with each other?
Answer:
Kerosene and petrol are separated by using distillation process because the difference in boiling point is more than 25°C.

Question 18.
What type of mixtures are separated by the techniques of crystallisation?
Answer:
Salt from water, sugar from water and sodium chloride from its solution in water, etc. are the mixtures to be separated by the techniques of crystallisation.

9th Class Physical Science 3rd Lesson Is Matter Pure? 2 Marks Important Questions and Answers

Question 1.
What is a centrifuge? What are its uses?
Answer:
Centrifuge is a machine used to separate the particles of higher mass and lower mass from a mixture.
Uses :

1. To separate cream from milk.
2. In diagnostic laboratories, to test blood and urine samples.
3. Dryer in a washing machine.

Question 2.
Define a mixture and mention its properties.
Answer:
Mixture :
A mixture is generally made of two or more components that are not chemically combined.

Properties :

1. The substances in a mixture retain their own properties.
2. The substances in a mixture can be physically separated.

Question 3.
What are homogeneous and heterogeneous mixtures? Give examples.
Answer:
Homogeneous mixture:
A homogeneous mixture is a mixture in which the components of the mixture are uniformly distributed throughout it.
Ex :
Lemonade, sugar solution, etc.

Heterogeneous mixture :
A heterogeneous mixture is a mixture made up of different substances or the same substance in different states which are not uniformly distributed in it.
Ex :
Oil and water; Naphthalene and water, etc.

Question 4.
Define solution, solvent and solute.
Answer:
Solution :
The homogeneous mixture of two or more substances is that we cannot separate them by the process of filtration called a solution.

Solvent:
The component of the solution that dissolve the other component in it (usually the component present in larger quantity) is called solvent.

Solute :
The component of the solution that is dissolved in the solvent (usually the component present in lesser quantity) is called solute.

Question 5.
Mention the properties of a solution.
Answer:

1.  The particles of a solution cannot be seen with our naked eye.
2. They do not show Tyndall effect.
3. The solute particles do not settle down when left undisturbed.
4. Solution is a homogeneous mixture.

Question 6.
What are the disperse phase and dispersion medium of a colloidal solution?
Answer:
Disperse phase :
Disperse phase is the substance that present in small proportions and consists of particles of colloidal size (lnm to 100 nm).

Dispersion medium :
Dispersion medium is the medium in which the colloidal particles are dispersed.

Question 7.
Define miscible and immiscible liquids.
Answer:
Miscible liquid :
A liquid is said to be miscible if it dissolve completely in another liquid.
Ex : Alcohol is miscible in water.

Immiscible liquid :
An immiscible liquid is one which doesn’t dissolve but forms a layer over another liquid and can be separated easily.
Ex : Oil is immiscible in water.

Question 8.
Define element and compound. Give examples.
Answer:
Element:
Element can be defined as a basic form of matter that cannot be broken down into simpler substances by chemical reactions.
Ex : lron, gold, silver, sodium, magnesium, etc.

Compound :
Compound can be defined as pure substance that can be separated into two or more components by means of chemical reactions.
Ex : Copper sulphate, ammonium chloride, etc.

Question 9.
How do you appreciate the efforts of scientists in discovering elements?
Answer:

• Generally elements are available in nature in the form of their ores.
• Study of properties of elements lead to the development of civilization.
• The efforts of early alchemists-up to and including Newton, Hennig Brand, Sir Humphry Davy are appreciable for their works in unearthing new elements.
• The definition of element and compound given by Robert Boyle and Lavoisier lead to study the properties of elements and compounds.

Question 10.
Name the technique to separate,
i) butter from curd
ii) salt from sea-water
iii) camphor from salt
Answer:
i) Centrifugation method is used to separate butter from curd .
ii) Crystallisation is used to separate salt from water.
iii) Sublimation technique is used to separate camphor from salt.

Question 11.
What are the factors on which solubility depends on?
Answer:
The factor influence solubility are

1. nature of solute
2. nature of solvent
3. temperature.

Question 12.
What is a concentrated and dilute solution?
Answer:
If the amount of solute is less in a solution, then it is called dilute solution.

If the amount of solute is more in a solution, then the solution is called concentrated solution.

Question 13.
How do you separate following mixture?
a) Iodine from sodium chloride
b) Petrol from water
c) Butter from milk
d) Sugar from water
Answer:
a) Sublimation
b) Separating funnel
c) Centrifugation
d) Evaporation

Question 14.
Identify pure substance and mixture from this figure. Why?

Answer:
a) Fig ‘a’ is a pure substance. Because particles are evenly distributed.
b) Fig ‘b’ is a mixture. Because particles are unevenly distributed.

9th Class Physical Science 3rd Lesson Is Matter Pure? 4 Marks Important Questions and Answers

Question 1.
Define the terms :
a) Solubility
b) Saturated solution
c) Unsaturated solution
d) Concentration
Answer:
a) Solubility :
The amount of solute present in a saturated solution at a certain tem-perature is called its solubility.

b) Saturated solution :
When no more solute can be dissolved in the solution at a certain temperature, it is said to be a saturated solution.

c) Unsaturated solution :
If the amount of solute present in the solution is less than that in the saturated solution is called an unsaturated solution.

d) Concentration of a solution:
The concentration of a solution can be defined as the amount (mass) of solute present in a given amount (mass) of solution or the amount (mass) of solute dissolved in a given volume of the solution.

Question 2.
Compare the properties of suspensions and colloids.
Answer:

Suspensions	Colloids
1. Suspensions are heterogeneous mixtures.	1. Colloids are heterogeneous mixtures.
2. The particles of suspensions can be seen with naked eyes.	2. The size of particles of a colloid are too small to be individually seen by naked eyes.
3. The particles of a suspension scatter a beam of light passing through it and make its path visible.	3. The particles of colloids are big enough to scatter a of light passing through it which makes its path visible.
4. The solute particles settle down when suspensioin is kept undisturbed. When the particles settle down it does not scatter light any more.	4. The particles don’t settle down when the colloid left undisturbed, i.e., colloid is quite stable.
5. Suspension is unstable. The components can be separated from the mixture by the process	5. The components cannot be separated from the mixture by the process of filtration or decantation Centrifugation technique is used in separation.

Question 3.
Explain the process of preparation of ice cream.
Answer:

1. Ice cream is made by churning a mixture of milk, sugar and flavours.
2. This mixture is slowly chilled to form ice cream.
3. The churning process disperses air bubbles into the mixture by foaming and break up the large ice crystals into tiny particles.
4. The result is a complex substance which contains solids, liquids and gases.
5. This is the ice cream.
6. Ice cream is a colloid.

Question 4.
What is chromatography? What are its uses?
Answer:
Chromatography :
Chromatography is a laboratory technique for the separation of mixtures into its individual components.
Uses:

1. Used to separate components of ink and dyes.
2. Used to separate the coloured pigments in plants.
3. Used to determine the chemical composition of many substances.
4. Used in crime scene investigations.
5. Used in hospitals to detect alcohol levels in a patient’s blood stream.
6. Used by environmental agencies to detect the level of pollutants in water supplies.
7. Used by pharmacists to determine the amount of each chemical found in each product.

Question 5.
Explain the process of separation of components of air briefly.
Answer:

1. If we want oxygen gas from air, we have to separate out all the other gases present in air.
2. The air is compressed by increasing the pressure and then cooled by decreasing the temperature to get liquid air.
3. This liquid air is allowed to warm up slowly in a fractional distillation column where gases get separated at different heights depending upon their boiling points.

Question 6.
Distinguish between mixtures and compounds.
Answer:

Mixtures	Compounds
1. Elements or compounds just mix together to form a mixture and no new compound is formed.	1. Elements react to form new compounds.
2. A mixture has a variable composition.	2. The composition of each new substance is always fixed.
3. A mixture shows the properties of the constituent substances.	3. The new substance has totally different properties.
4. The constituents can be separated fairly easily by physical methods.	4. The constituents can be separated only by chemical or electrochemical reactions.

Question 7.
Draw a flow chart shows the process of obtaining gases from air.
Answer:

1. We have learnt that air is a homogeneous mixture.
2. It can be separated into its components.
3. The following are the steps involved in separating the components of air.

Question 8.
Draw a flow chart to understand the chemical and physical nature of the matter.
Answer:

Question 9.
Give some daily life experiences where you can observe “Tyndall effect”.
(OR)
What is Tyndall effect? Write any two applications of Tyndall effect.
Answer:
Tyndall effect:
Scattering a beam of light is called the ‘Tyndall effect’.

Daily life experiences:

1. Select a room where the sun light falls directly through a window.
   Close the window in such a way that a slit is left open between the windows.
   We observe a beam of light passing through the slit.
2. While walking on a road having a lot of trees on both sides, when the sun light passes through branches and leaves, we can see the path of dust particles.
3. In cinema halls we can observe the beam of light scatters from projector to the screen.
4. When smoke in the kitchen is exposed to sun light, we can observe the path of smoke particles.

Question 10.
How do you separate the mixture of napthaleine powder and salt powder?
Answer:
Aim :
To separate components in the mixture of napthaleine and salt.

Apparatus:
China dish, cotton plug, funnel, burner.

Method :
Separation mixtures by sublimation.

Procedure :

1. Take 4 table spoons of mixture in a China dish.
2. Take the glass funnel and plug the mouth of the funnel with cotton plug.
3. Invert the funnel over the China dish.
4. Keep the dish on the stand of stove and heat for some time.

Observation :

1. Vapours of napthaleine solidified on the walls of the funnel.
2. Salt remains in the China dish.

These AP 9th Class Biology Important Questions 10th Lesson Soil Pollution will help students prepare well for the exams.

AP State Syllabus 9th Class Biology 10th Lesson Important Questions and Answers Soil Pollution

9th Class Biology 10th Lesson Soil Pollution 1 Mark Important Questions and Answers

Question 1.
What will happen if there is increase in acidic or basic nature of soil?
Answer:

• The nutrients available to plants will be greatly reduced by increase in acidic or basic nature of soil.
• This results in the decrease of plant yield.

Question 2.
What is decomposition?
Answer:
Decomposition is the process of materials being digested and broken down into simpler substances, making nutrients more available to plants.

Question 3.
What are the effects of toxic chemicals released into the soil?
Answer:
Toxic chemicals leached from oozing storage drums into the soil, underneath homes, causing an unusually large number of birth defects, cancers and respiratory, nervous and kidney diseases.

Question 4.
What is bioremediation?
Answer:
The process of using microbes to clear up the contamination in soil and water is called bioremediation.

Question 5.
What is mineralization?
Answer:
The process of converting organic elements to inorganic forms and liberating C02, ammonia, sulphate, phosphate etc…. is called mineralization.

Question 6.
What is soil erosion?
Answer:
The removal of top layer of the soil by wind, rainfall is called soil erosion.

Question 7.
What is top soil comprised of?
Answer:
Humus, living organisms and soil particles are present in the top soil.

Question 8.
What is soil profile?
Answer:
Soil profile is the vertical section of earth’s crust generally up to the depth of 1.83 metres.

Question 9.
Name the three natural resources on the earth.
Answer:
Air, water and land.

Question 10.
What is soil?
Answer:
The top most layer of the lithosphere is called soil.

Question 11.
Fertile soils have lots of humus. Why?
Answer:
Fertile soil is rich in organisms that decompose dead organic matter into humus. Humus gives minerals, absorb water and makes soil porous.

Question 12.
Why step farming is common in hills?
Answer:
Step farming is common in the hills to check soil erosion through water currents on the slopes.

Question 13.
What are the factors determining the soil type?
Answer:
The soil type depends on
a) Amounts of humus
b) Size of the soil particles
c) Microorganisms present in the soil.

9th Class Biology 10th Lesson Soil Pollution 2 Marks Important Questions and Answers

Question 1.
What are the components of soil?
Answer:

• Soil is made up of minerals and decomposed organic matter, along with air and water.
• Soil can create a habitat for fungi, bacteria and related organisms which in turn, feed and support plants life.

Question 2.
Write a short note on biodegradable waste. Give examples.
Answer:

• Substances that can be degraded by microbes into harmless and toxic substances are known as biodegradable waste.
• Agricultural and animal wastes like leaves, twigs, hay, dung etc., are examples for biodegradable wastes.

Question 3.
Write a short note on non-biodegradable waste. Give examples.
Answer:

• Substances that cannot be easily degraded are non-biodegradable substances.
• Aluminium cans, plastics, glass, DDT etc., are examples of non-biodegradable wastes.

Question 4.hat is soil erosion? What are causative factors for soil erosion?
Answer:

• Soil erosion occurs when the weathered soil particles are dislodged and carried away by wind or water.
• Deforestation, agricultural development, temperature extremes, precipitation including acid rain and human activities contribute to soil erosion.
• Humans speed up this process by construction, mining, cutting of timber, over¬cropping and overgrazing.
• It results in floods and cause soil erosion.

Question 5.
What are the problems that arise due to uncollected and decomposed solid waste in cities?
Answer:
If solid waste left uncollected and decomposed, they are a cause of several problems such as

1. Clogging of drains
2. Barrier to movement of water
3. Foul smell
4. Increased microbial activities
5. Create health problems if they are solid wastes of hospital.

Question 6.
What will happen if you throw the wastes wherever you want?
Answer:

1. They pollute our surroundings.
2. These wastes cause land pollution.
3. These wastes spread diseases.
4. They show effect on the health of human beings.

Question 7.
What are the effects of soil pollution on agriculture?
Answer:

1. Reduced soil fertility.
2. Reduced nitrogen fixation.
3. Increased erodibility.
4. Larger loss of soil and nutrients.
5. Deposition of silt in tanks and reservoirs.
6. Reduced crop yields.
7. Imbalance in soil fauna and flora.

Question 8.
What are the effects of soil pollution due to industrial waste?
Answer:

1. Dangerous chemicals entering underground water.
2. Ecological imbalance.
3. Release of pollutant gases.
4. Release of radioactive rays causing health problems.
5. Increased salinity.
6. Reduced vegetation.

Question 9.
What are the effects of soil pollution due to urban activities?
Answer:

1. Clogging of drains
2. Inundation of areas
3. Public health problems
4. Pollution of drinking water sources
5. Foul smell and release of gases
6. Waste management problems

Question 10.
What are Bio-degradable pollutants? Give examples.
Answer:
The pollutants that are degraded by natural means are called Bio-degradable pollutants.
Eg : Paper, wood, leaves, etc

Question 11.
Enlist the main causes of soil erosion.
Answer:
(a) Deforestation
(b) Urbanisation
(c) Excessive over grazing
(d) Leaving the land uncultured for a long time.

Question 12.
Fill this flow chart.

Answer:

1. Contour ploughing
2. Planting trees
3. Crop Rotation
4. Salinity Management

Question 13.
Fill this flow chart.

Answer:

1. Reusing of materials
2. Recycling and recovery of materials
3. Reforesting
4. Reducing chemical fertilizer and pesticides use.

Question 14.
Fill this flow chart.

Answer:

1. Agricultural soil pollution
2. Soil pollution by industrial effluents and solid wastes
3. Pollution due to urban activities.

9th Class Biology 10th Lesson Soil Pollution 4 Marks Important Questions and Answers

Question 1.
How soil is formed?
Answer:

• Soil formation is a long and complex process and it can take 100 to 10,000 years to create one inch of top soil.
• The factors responsible for soil formation are climate, topography, living organisms and the type of parent material.
• Parent materials come from breakdown of underlying rocks or from deposits by streams and rivers, seas and gulfs, hills, wind and glaciers or organic plant residues.
• Over time, these materials are weathered by the effect of freezing, thawing, wetting, drying, heating, cooling, erosion, plants and animals and from chemical reactions.
• Eventually, the parent material is divided into three horizontal layers, the top layer consists of mostly organic matter and biological activity.
• The middle layer is the zone of maximum material accumulation.
• The bottom layer bold is mainly the parent material, but slightly altered.
• The top soil is important since it is the foundation for the life on the earth.

Question 2.
What are the chemical properties of soil? What effects do this have on the plants?
Answer:

• The term pH is used to indicate the level of acidity or alkalinity of a soil.
• The range of pH values of a good soil lies from 5.5 to 7.5.
• Below pH 7 the soils are termed as acidic and above pH 7 alkaline.
• The pH of soil is important in determining the type of vegetation that will grow in the soil.
• Availability of plants nutrients is strongly tied to the pH in soil.
• The availability of N, K, Ca, Mg and S tends to decrease with decreasing pH.

Question 3.
What are the biological properties of soil? What effects do this have on plants?
Answer:

• Soil is the most abundant and diverse ecosystem on the earth.
• Soil organisms include both plants and animal forms ranging from submicroscopic viruses to earthworms, to large burrowing animals such as gophers (rats) and ground squirrels.
• Major microbial groups in soil are bacteria, fungi, algae and protozoa.
• These feed on plant residues burrow the soil and help in aeration and percolation of water.
• Soil microbes convert organic forms of elements to their inorganic forms and liberate carbon dioxide, ammonia, sulphate, phosphate and inorganic forms of other elements. This process is known as mineralization.
• Soil bacteria control the forms of ions in which these nutrients occurs.

Question 4.
Write the effects of insecticide DDT on environment.
Answer:

• The first widespread insecticide use began at the end of world war 11 that included DDT and gamanaxene.
• Insect soon became resistant to DDT and as the chemical did not decompose readily, it persisted in the environment.
• Since it was soluble in fat rather than water, it biomagnified up the food chain and disrupted calcium metabolism in birds, causing egg shells to be thin and fragile.
• As a result, large birds of prey such as the brown pelican, ospreys, falcons and eagles became endangered.
• DDT is now banned in most of the western countries.

Question 5.
Write the examples of pesticides. What are their effects on soil and human beings?
Answer:

• Besides DDT the most important pesticides are Benzene hexachloride (BHC), chlorinate dihydro carbons, organophosphates, aldrin, malathion, dieldrin, furodan etc., are the examples.
• The remnants of such pesticides used on pests may get absorbed by the soil particles, which then contaminate root crops grown in that soil.
• The consumption of such crops causes the pesticides remnants to enter human biological systems, affecting them adversely.
• Pesticides not only have toxic effect on human and animals but also decrease the fertility of the soil.
• Some of the pesticides are quite stable and their biodegradation may take weeks and even months.

Question 6.
Write briefly about biomagnification.
Answer:

1. The nutrients necessary for plant growth are found at very low concentrations in most natural waters.
2. In the process of collecting nutrients, phytoplankton also collects certain human made chemicals such as some persistent pesticides.
3. These may be present in the water at a very low concentrations that they cannot be measured even with a very sensitive instruments.
4. The chemicals however, biologically accumulate in the organism and become concentrated at levels that are much higher in the living cells than in the open water.
5. The small fish and zooplankton eat vast quantities of phytoplankton.
6. In doing so, any toxic chemicals accumulated by the phytoplankton are further concentrated in the bodies of the animals that eat them.
7. This is repeated at each step in the food chain.
8. This process of increasing concentration through the food chain is known as bio-magnification.

Question 7.
What is solid waste? What are different types of solid waste?
Answer:
1. Solid waste may be defined as the organic and inorganic waste produced by various activities of the society which have lost their value to the first user.

2. Solid waste, on the basis of its sources of origin can be classified as
a) Municipal solid waste :
It consists of household waste, construction and demolition debris, sanitation residue.

b) Hazardous solid waste :
Industrial and” hospital waste is considered to be hazardous waste as they contain toxic substances.

c) Infectious solid waste:
Biomedical or hospital waste generated during diagnosis, treatment etc., which include sharp chemical wastes, discarded medicines and human excreta.

Question 8.
What are the different ways and methods possible for soil conservation? Briefly explain them.
Answer:
There are several ways possible for soil conservation. They are planting trees, terraces, no-till farming, contour ploughing, crop rotation, soil pH, watering the soil, salinity management, soil organisms and indigenous crops.

1. Planting trees :
a) Soil that is under a vegetative cover has hardly any chance of getting eroded as the vegetative cover acts as a wind barrier.
b) As the roots of the trees spread deep into the layers of soil they contribute to the prevention of soil erosion.

2. Terraces :
a) A terrace is a leveled section of hilly cultivated area.
b) Owing to its unique structure, it prevents the rapid surface runoff of water.

3. No-till farming : It is a way of growing crops without disturbing it through tillage.

4. Contour ploughing :
a) It is the method of ploughing across the contour lines of a slope.
b) This method helps in slowing the water runoff and prevents the soil from being washed away along the slope.

5. Crop rotation: Crop rotation helps in the improvement of soil structure and fertility.

6. Soil pH :
Maintenance of the most suitable value of pH is essential for the conservation of soil.

7. Water the soil :
Watering the soil along with the plants is a way to prevent soil erosion caused by wind.

8. Salinity management :
a) If salinity of the soil increases it results in the death of vegetation.
b) The death of vegetation is bound to cause soil erosion.
c) Hence salinity management is one of the indirect ways to conserve soil.

9. Soil organisms :
The helpful organisms of soil promote its fertility and form an element in the conservation of soil.

10. Indigenous crops :
Planting of native crops is known to be beneficial for soil conservation.

9th Class Biology 10th Lesson Soil Pollution Important Questions and Answers

Question 1.
Write any two preventive measures for fluorosis.
Answer:

• Use river water in place of groundwater.
• Use rainwater and groundwater with less fluoride percentage.
• By using defluoridation method, fluorides can be removed from water.

Question 2.
Look at the picture and answer the questions below.

a) Which substance cause less soil pollution?
b) Which of the above pollutants can be biodegradable?
c) Give two examples of construction soil pollutants.
d) Mention any two preventive measures for soil pollution.
Answer:
1) Peat waste (1%).
2) Organic waste, peat waste, paper.
3) Construction and demolition, metals.
4) Using 4’R principle in our daily life implementing comprehensive solid waste management.

Question 3.
You know that Fluoride cause health hazards, how can you aware people of your village regarding this?
Answer:

• Using surface water sources like rivers and streams.
• Defluoridation technique is very useful in getting Fluorine free water.
• We should not consume the vegetables which are grown in high Fluoride soils.

Question 4.
Plastic is harmful to the environment. What will you do to replace it?
Answer:
We should use paper bags, jute bags and cloth bags in place of plastic bags.

Question 5.
Ravi decided not to use plastic bags. What alternative methods will you suggest?
Answer:

• Using jute covers and cloth bags in place of plastic bags.
• Using bamboo baskets in place of large plastic covers to store and carry goods.

Question 6.
There is an ecosystem, where industrial sewage occurs. Arrange the following living organisms in various trophic levels as per the persistent. (Biomagnification).
Grass, Fish, Sheep, Grass hopper, Phytoplankton, Prawn, Crow, Frog, Larval forms.

Answer:

Question 7.

Observe the above diagram, answer the following questions.
i) Name the pollutant which pollutes the soil the most.
ii) Write the biodegradable materials given in the figure.
iii) What will happen if the usage of plastic increased?
iv) What metals pollute the soil, due to the excessive usage of Super Phosphate fertilisers in cultivation?
Answer:
i) Organic wastes 32%
ii) Organic wastes and paper
iii) They remain in the soil for several hundreds of years. They cause a lot of soil pollution. They damage the soil health.
iv) Nitrates and phosphates

These AP 9th Class Social Studies Important Questions 20th Lesson Democracy: An Evolving Idea will help students prepare well for the exams.

AP State Syllabus 9th Class Social 20th Lesson Important Questions and Answers Democracy: An Evolving Idea

9th Class Social 20th Lesson Democracy: An Evolving Idea 2 Marks Important Questions and Answers

Question 1.
What is the most important reason to vote for and elect leaders in a democracy? (SA-II : 2018-19)
Answer:
Democracy is completely based on voting system.

• Right to vote create a chance to voters to select good government.
• People select the leader who is capable and solve their problems.
• Right to vote is most important, because people should express their opinion.

9th Class Social 20th Lesson Democracy: An Evolving Idea 4 Marks Important Questions and Answers

Question 1.
“Democracy which respects the freedom and rights of all people may be the best way to solve some of the complex problems the countries in the present day world.’
Do you agree which this statement? Justify your answer. (SA-II : 2018-19)
(OR)
Today a new kind of democracy is been forged across the world in which even the poorest and most vulnerable people will have a voice and will be able to influence policies and ensure justice and peace for all.
“Democracy is the best form of Government”. Comment on it. (SA-II : 2017-18)
Answer:
Democracy is the best form of government by following ways.

1. Democracy provide freedom.
2. Democracy represents the people.
3. It is better governance due to transparency.
4. Democracy gives respect to human rights.
5. It promotes the human rights.
6. It gives more freedom of speech and expression.

9th Class Social 20th Lesson Democracy: An Evolving Idea Important Questions and Answers

Question 1.
Observe the following table and answer the given questions.

Inequality of Incomes in Selected Countries
Country	Share of National Income (%)
	Top 20	Bottom 20
South Africa	64.8	2.9
Brazil	63.0	2.6
USA	50.0	4.0
United Kingdom	34.5	9.6
Dennsik	34.5	9.6
Hungary	34.5	10.0

1) Which country has more inequality?
Answer:
South Africa

2) What is the difference in USA?
Answer:
46

3) Among the given countries, which is the South American country?
Answer:
Brazil

4) Which country has least difference?
Answer:
Hungary

Question 2.
Read the following passage and answer the given questions.
Belgium : Belgium is a small country in Europe. Of the country’s total population, 59 per cent lives in the Flemish region and speaks Dutch language. Another 40 percent people live in the Wallonia region and speak French. Remaining one per cent of the Belgians speak German. In the capital city Brussels, 80 per cent people speak French while 20 per cent are Dutch- speaking.
1) Where is Belgium?
Answer:
Belgium is a small country in Europe.

2) Who speaks Dutch language?
Answer:
59% of population of Belgium lives in the Flemish region and speaks Dutch language.

3) Who speaks French?
Answer:’
40% lives in the Wallonia region and speaks French.

4) What per cent of people speak German?
Answer:
One per cent of people speak German.

5) What is the capital city of Germany?
Answer:
Brussels.

Question 3.
Read the following passages and answer the given questions.
In Sri Lanka, post its independence in 1948, the leaders of the Sinhala community sought to secure dominance over government by virtue of their majority. As a result, the democratically elected government adopted a series of majoritarian measures to establish Sinhala supremacy.

Sinhala was made the only official language, disregarding Tamil. The governments followed preferential policies that favoured Sinhala applicants for jobs. A new constitution stipulated that the state shall protect and foster Buddhism. All these government measures, coming one after the other, gradually increased the feeling of alienation among the Sri Lankan Tamils.

1) When did Sri Lanka get its independence?
Answer:
In 1948.

2) What community is mentioned here?
Answer:
Sinhala community.

3) What did the democratically elected government adopt?
Answer:
The democratically elected government adopted a series of majoritarian measures to establish Sinhala supremacy.

4) Sinhala was made the only official language, disregarding ___________
Answer:
Tamil.

5) A new constitution stipulated that the state shall protect and foster ___________
Answer:
Buddhism.

These AP 9th Class Social Studies Important Questions 9th Lesson Credit in the Financial System will help students prepare well for the exams.

AP State Syllabus 9th Class Social 9th Lesson Important Questions and Answers Credit in the Financial System

9th Class Social 9th Lesson Credit in the Financial System 1 Mark Important Questions and Answers

Question 1.
Expand NABARD. (SA-III : 2015-16)
(OR)
Explain the term NABARD. (SA-II : 2017-18)
Answer:
National Bank for Agricultural and Rural Development.

9th Class Social 9th Lesson Credit in the Financial System 2 Marks Important Questions and Answers

Question 1.
500 and 1000 rupees notes were demonetized recently. How far is this helpful for Indian economy in your opinion? (SA-III : 2016-17)
Answer:
The decision of the government to scrape 500 and 1000 currency notes is affecting different class of society in a different way.
Poor class :
This class is affected adversely immediately. Because they use debit or credit card is very less.

Temporarily they face problem but they become normal within month.

Middle class :
They too have to stand on a big queue for short time because they still need the 100 rupee note, for making petty payments.

Upper class :
They too may face trouble for few days but their life would become normal very soon.

Long term benefits :

1. Developmental activities would pick up significantly as the tax revenue increases.
2. Corruption would reduce.
3. Government can reduce rates of taxes.
4. Illegal activities would reduce.
5. Dowry and other social practices like extravagant marriages would reduce due to white economy.

Question 2.
What do the banks do with the deposits which they collect from the public? (SA-III : 2016-17)
Answer:

• Banks keep only a small proportion of their deposits as cash with themselves.
• Banks in India these days hold about 15% of their deposits as cash.
• This is kept as provision to pay the depositors who might come to withdraw money from the bank on any given day.
• Banks use the major portion of the deposits to extend loans.
• There is a huge demand for loans for various economic activities.

Question 3.
Financial literacy is the process of equipping oneself with knowledge and information on financial matters. Taking interest in financial literacy helps one to goals and protect oneself from frauds and debts traps. It aims inculate savings habits improve the understanding of financial products leading to effective use of financial services and thus helps better money management further financial literacy facilitates easy access to financial services.
“Financial literacy is an important for consumer protection and financial stability”? Comment on it. (SA-II : 2016-17)
Answer:
Importance of Consumer protection and Financial literacy :

1. Ensure that financial markets are deep and serve the broad population.
2. Provide access to financial services for low income households and
3. Ensure long-term stability in the financial system.
4. Financial markets help to build consumer trust in financial institutions and ensure that financial institutions reach out to serve the needs of the population, including low-income households that often lack access to basic financial services.

Question 4.
Appreciate the role of self-help groups to fulfill the financial needs of poor women. (SA-II : 2016-17)
(OR)
Self help groups are the building blocks of organisation of the rurql and urban poor. Not only do women become financially self reliant, it is a platform to discuss and act on a variety of social issues such as health, nutrition, domestic violence etc.”
Do you agree with the above statement? Explain your answer. (SA-II : 2018-19)
Answer:

• The Self Help Groups played a very significant role in empowering rural women in India.
• Self Gelp Group fulfill the commercial requirements of poor women members by doing the small amount of daily savings and making contributions for few months till the time there is sufficient funds in the group to start lending.
• To empower the women they provide buffaloes on loan, sewing machines, and provide loan for small general stores etc.
• Not only these the SHG group protect the women from domestic violence and from social abuse etc.
• SHG’s work for rural and urban poor women.

9th Class Social 9th Lesson Credit in the Financial System 4 Marks Important Questions and Answers

Question 1.
“There are some major differences between the way formal and informal credit providers operate in India. While the formal credit providers follow certain rules and regulations framed by government, informal credit providers do not follow such rules. When the borrower could not repay as per the agreed terms, formal credit providers cannot use any illegal ways to get back the credit, whereas informal credit providers use many coercive and illegal ways which at times lead to borrowers committing suicides. Compared to the formal lenders, most of the informal lenders charge a much higher interest on loans. Banks and cooperative societies need to lend more. This would lead to higher incomes because many people could then borrow cheaply for a variety of different needs. They could grow crops, do business, set up small-scale industries etc. They could set up new industries or engage in business activity. Cheap and affordable credit for all is crucial for the country’s development.”
Q. “The rich households are availing cheap credit from formal lenders whereas the poor households have to pay a heavy price for borrowing from informal sources” – Comment in your own words. (SA-III : 2016-17)
Answer:
The main reason behind poor house holds depends on informal lenders/sources because banks do not wish to give loans to the poor, who have no collateral. Bank loans require proper documents and collateral. Banks prefer not to lend money to the poor farmers and landless labourers, because more often than not they don’t have the required documents to take loan.

But rich people have more properties, they should submits proper documents to banks for loan.

According to this, rich people are benefited with low rate of interest but poor people are suffered with high rate of interest.
So formal sector loans need to expand in rural areas for the development of poor.

Question 2.
What are the various services provided by the bank to the customers? (SA-II : 2018-19)
Answer:
Financial institutions means banks may differ in the type and number of services they provide to customers.

The services most often provided include a variety of checking accounts, savings accounts; certificates of deposits, and loans, including car loans and home mortgages.

Additional services may include safe deposit boxes and investment related services. Education loans to students also.

9th Class Social 9th Lesson Credit in the Financial System Important Questions and Answers

Question 1.
What are the two important functions of Banks?
Answer:
All commercial banks perform the following two functions.

1. Banks accept deposits from the customers and pay an interest on the deposits.
2. Banks lend loans to the customers and charge interest on the loans.

Question 2.
What is the primary source of income for banks?
Answer:
The difference between what is charged from borrowers and what is paid to the depositors is the primary source of income for banks.

Question 3.
What is meant by the term ’credit1 (loan)?
Answer:

• Credit refers to an agreement in which the lender supplies the borrower with money, goods or services in turn for the promise of future payment.
• Credit helps us to meet our needs or expenses.

Question 4.
What is meant by the term collateral?
Answer:
Collateral is an asset that the borrower owns (such as land, building, vehicles, livestock, deposits with bank) and uses this as a guarantee to a lender until the loan is repaid.

Question 5.
What are formal and informal sources of credit in India?
Answer:

• The various types of loans can be conveniently grouped as formal sector loans and informal sector loans.
• Among them, formel are loans from banks and cooperatives.
• The informal lenders include moneylenders, traders, employers, relatives and friends, etc.

Question 6.
What is meant by the word ’financial literacy’?
Answer:

• Financial literacy is the process of equipping oneself with knowledge and understanding on financial matters and to take right financial decisions leading to financial confidence.
• Simply, taking efforts to equip oneself with knowledge on financial matter.

Question 7.
Where do we get information regarding financial literacy?
Answer:

• Financial literacy material is available on the website of Reserve Bank of India.
• In addition, for the benefit of word illiterate persons in rural and urban and remote areas, State Level Bankers Committee (SLBC), AP has prepared an audio CD on the benefits of saving with banks.

Question 8.
What are “the terms of credit”?
Answer:
Interest rate, collateral and documentation requirement and the mode of repayment together comprise what is called the terms of credit.

Question 9.
Why do you think bank deposits are called ‘demand deposits’?
Answer:

• Banks accept the deposits and also pay an amount as interest on the deposits.
• People have the right to withdraw the money as and when they require.
• Since the deposits in the bank accounts can be withdrawn on demand, these deposits are called ‘demand deposits’.

Question 1o.
Why do you think the people in rural areas demand for credit?
Answer:

• In the rural areas, the main demand for credit is for crop production.
• Crop production involves considerable costs on seeds, fertilizers, pesticides, water, electricity, repair of equipment, etc.
• Farmers usually take crop loans at the beginning of the season and repay the loan after harvest.
• There is usually 3 to 4 months gap between farmers buying inputs and selling the crop.
• Repayment crucially depends on income from farming.

Question 11.
Read the passage and answer the following questions.

The RBI has now initiated processes of improving the financial access to people in rural areas. All banks would be opening rural accounts using Business Facilitators and Business Correspondents. These correspondents would encourage people in rural areas to open bank accounts so that they can save their money and also use loan facilities of the bank. These facilitators would help them connect with the local branch. Electronic identification systems would be used to open these accounts. Recently, the government initiated providing Unique Identification Number to every citizen of India. All those who have enrolled themselves and given a card called Aadhaar. Those who have this number can open the bank account easily and also get the benefits and services provided by government. Earlier banks used to make it mandatory to put a minimum amount while opening an account. Nowadays, can open account and there is no compulsion to keep any minimum amount. This is called ‘Basic Savings Bank Deposit Account’ (BSBDA).

1) What has RBI initiated?
Answer:
The RBI has now initiated processes of improving the financial access to people in rural areas.

2) What would be the uses of RBI’s steps?
Answer:
They would encourage people in rural areas to open bank accounts, to save money ’ and also use loan facilities of the banks.

3) What initiations has the government taken recently?
Answer:
Recently, the government initiated providing unique identification number to every citizen of India.

4) What is the name of the card?
Answer:
Aadhaar card.

5) Is there any mandatory to put a minimum account?
Answer:
Now, there is no compulsion to keep a minimum amount. This is called ‘Basic Savings Bank Deposit Account’.

Question 12.
Understand the Pie diagram and fiSi the table.

Sources of credit for rural Households in India in 2003

Read the above table and Answer the following questions.
1) Note the change in the loans issued by all formal organizations for the last three decades.
Answer:
The loans issued by formal organizations has increased from 15.8% in 1961 to 52% in 2003. There is an increase of 36.2%.

2) What was the difference in the loans issued by all informal organizations for the last three decades?
Answer:
The loans issued by informal organizations have been reduced from 84.0 to 48%. There is a decrease of 36%

Question 13.
What are the reasons for farmers distress in Andhra Pradesh?
Answer:

• Most of the farmers take loans to meet the expenses of cultivation.
• When crops fail, they cannot repay the loans.
• Again they take a fresh loan from informal lenders.
• Finally fallen in debt-trap and this leads to distress among them.

Question 14.
What are the reasons for the poor notable to get bank loans, nowadays?
Answer:

• Bank loans require proper documents and collateral.
• Absence of collateral is one of the major reasons which prevent the poor from getting bank loans.
• They have a few assets to keep as collateral.
• They are going to easily accessible informal loans.

Question 15.
How is cheap and affordable credit for all, crucial for the country’s development nowadays?
Answer:

• Borrowing at higher rates of interest makes borrowers to have left with less income for themselves.
• In somecases it may be more than his income and leading to debt trap.
• For this reasons, banks and cooperatives need to lend more.*
• As these offer loans at lower rate of interest, borrowers use them for a variety of needs.
• Thus the availability of cheap and affordable credit for all is crucial for the country’s development nowadays.

Question 16.
Study the following pie-chart.

1) What does the above chart describe?
Answer:
It describes the distribution of credit among different households.

2) Describe the pie-chart.
Answer:

• Out of total credit, poor households take 40% of the credit.
• Out of total credit, rich households take 21% of the credit.
• Well-off households take 32% of credit and stood 2nd place in availing credit.
• Households with few assets take least percentage of loans, i.e. only 7%.

Question 17.
What is the measure taken by government and Non-governmental Organizations to organize rural poor?
Answer:

• In recent years government and NGOs have found new way for providing loans to the poor.
• The idea is to organize rural poor, particularly women into small Self Help Groups (SHGs) and pool their savings.
• SHGs with 15-20 members save Rs. 25 to Rs. 100, at least for 2 years.
• They can take small loans from group itself to meet their needs.
• Group charges small interest on borrowing members.
• After a year or two, they can get loan from bank without collateral.

Question 18.
What are the measures taken by RBI to help rural agriculture?
Answer:
1) The Reserve Bank of India sees that banks give loans not just to profit making business and traders but also to small cultivators, small scale industries, to small borrowers, etc.

2) In recent times, besides RBI, NABARD (National Bank for Agricultural and Rural Development) facilitates formal credit organisations in Rural India.

These AP 10th Class Physical Science Chapter Wise Important Questions 9th Lesson Classification of Elements- The Periodic Table will help students prepare well for the exams.

AP State Syllabus 10th Class Chemistry 9th Lesson Important Questions and Answers Classification of Elements- The Periodic Table

10th Class Chemistry 9th Lesson Classification of Elements- The Periodic Table 1 Mark Important Questions and Answers

Question 1.
What is modern periodic law? (AP June 2015)
Answer:
Modern periodic law :
The physical and chemical properties of the elements are periodic functions of their electronic configurations.

Question 2.
Define Moseley’s periodic law. (AP June 2015)
Answer:
Moseley’s periodic law: The physical and chemical properties of elements are periodic functions of their atomic numbers.

Question 3.
Which group elements are called Carbon family? (AP Mareh 2016)
Answer:
14 (or) IVA Group of elements are called Carbon family.

Question 4.
Which atom is bigger in size, Ne or Ar? Why? (AP June 2018)
Answer:
Ar. In groups as we go down number of shells increases due to the formation of new shell.

“O Group”

He

Ne

Ar

Kr

Xe

Rn

Question 5.
A and B are two elements. The compound formed with A and B is A₂ B. What are the valencies of A and B. (TS March 2018)
Answer:
The valency of A is 1 and B is 2.

Question 6.
A teacher asked to give an example for Dobereiner’s triad. Ramu wrote them as “Li, Na, Mg”. In these three, identify which element does not belongs to this triad? (AP March 2019)
Answer:
Mg or Magnesium do not belongs to this triad.

Question 7.
Write the difference between Mendeleeff’s periodic law and modern periodic law. (AP SCERT: 2019-20)
Answer:
Mendeleeff’s periodic table is prepared based on atomic mass whereas modem periodic table is prepared based on atomic number (electronic configuration).

Question 8.
What is Dobereiner Triad? Give two examples to it.
Answer:
A group of three elements in which atomic weight of middle element is average of first and third element is called Dobereiner triad with similar propertion.
Eg: 1) U, Na, K
2) Cl, Br, I

Question 9.
What is Newlands’ law of octaves?
Answer:
When elements are arranged in the ascending order of their atomic weights, every eighth element starting from a given element resembles in its properties to that of starting element. This is called Newlands’ law of octaves.

Question 10.
What is MendeleefFs periodic law?
Answer:
MendeleefFs periodic law:
The physical and chemical properties of the elements are the periodic functions of their atomic weight.

Question 11.
What is the name given to horizontal rows and vertical columns in MendeleefFs periodic table?
Answer:
Horizontal rows are periods and vertical columns are groups.

Question 12.
What is the property on which MendeleefFs periodic table depends upon?
Answer:
Mendeleeff’s periodic table depends upon atomic weight.

Question 13.
What is the name given to I(A) group elements?
Answer:
Alkali metal family, because aliquili = plant ashes. Na, K, etc. were obtained from plant ash.

Question 14.
Why are VI A group elements called chalcogens?
Answer:
Chalcogeneous = Ore product. As the elements in group 16 (VI A) form ores with metals, they are called chalcogeneous family.

Question 15.
Why are VII A group elements called halogens?
Answer:
Halos – sea salt, genus – produced. So VII A (17) are obtained from nature as sea salt. So they are called halogen family.

Question 16.
What are halogens?
Answer:
Fluorine, Chlorine, Bromine, Iodine, and Astatine of VIIA group elements are called halogens, which are obtained from sea salt.

Question 17.
What are noble gases? What is the general electronic configuration of noble gases?
Answer:
The elements of group VIII A (18) are chemically least reactive so they are called noble gases. Their group electronic configuration is ns²np⁶ (except) for helium it is 1s².

Question 18.
What are Lanthanides?
Answer:
Elements acquiring same properties are called lanthanides, i.e. 4f elements. They are from ₅₈Ce (Cerium) to ₇₁Lu (Lutetium).

Question 19.
What are Actinides?
Elements acquiring different properties are called actinides, i.e. 5f elements. They are from ₉₀Th (Thorium) to ₁₀₃Lr (Lawrensium).

Question 20.
What are metals and non-metals?
Answer:
The elements with three or less electrons in the outer shell are considered to be metals and the ore with five or more electrons in the outer shell are considered to be non-metals.

Question 21.
What are metalloids?
Answer:
The properties of elements which are intermediate between the properties of metals and non-metals are called metalloids.

Question 22.
Which will behave like semi-conductors?
Answer:
Metalloids or semi-metals behave like semi-conductors.

Question 23.
What is valency?
Answer:
The combining power of element with respect to hydrogen, oxygen or indirectly any other element through hydrogen and oxygen is called valency.

Question 24.
What is the latest definition of valency?
Answer:
The number of electrons lost or gained or shared during a chemical reaction.

Question 25.
How do we measure atomic radius of solids?
Answer:
It is half of the distance of radius of each atom.

Question 26.
What is covalent radius?
Answer:
Half of the distance between length of covalent bond is called covalent radius.

Question 27.
In which units is atomic radius measured?
Answer:
Atomic radius is measured in pico meter (pm) units.
1 pm = 10^-12 m.

Question 28.
What is the method given by Milliken to calculate electronegativity of an element?
Answer:
According to Milliken, electronegativity of element is average value of its ionization energy and electron affinity.

Question 29.
What is electropositive character?
Answer:
The tendency of metals to remain positive ions in compounds is called electropositive character. (OR) The tendency of an atom to lose electrons to form positive ions.

Question 30.
What is screening effect or shielding effect?
Answer:
More the shells with electrons between the nucleus and the valence shell, they act as screens to decrease nuclear attraction over valence electron. This is called screening effect or shielding effect.

Question 31.
What do you mean by negative or positive electron gain enthalpy?
Answer:
The negative sign indicates that energy is liberated or lost, and the positive sign indicates that the energy is gained or absorbed.

Question 32.
What is a triad?
Answer:
A group of three elements with similar properties in which atomic weight of middle element is average of other two elements.

Question 33.
Chlorine, bromine, iodine are Dobereiner’s triads. How do you justify?
Answer:
Chlorine, bromine and iodine have similar properties and atomic weight of bromine is average of chlorine and iodine.

Question 34.
Why are lanthanides and actinides placed separately at the bottom of the periodic table?
Answer:
Lanthanides and actinides belong to f – block elements with different properties so they are placed at the bottom of periodic table.

Question 35.
Lithium, Sodium, and Potassium were put in one group on the basis of their similar properties.
1) What are those similar properties?
2) What is the common name of this group of family?
Answer:

1. They have same number of valence electrons that is 1 and valency 1. So they have similar chemical properties.
2. They are called alkali metals.

Question 36.
What are the following groups known as?
1) group VIIA elements
2) Zero group elements.
Answer:

1. Group VII A elements are called Halogens.
2. Zero group elements are called Noble gases.

Question 37.
An element Barium lies in 2^nd group; then answer the following.
1) What is its valency?
2) What will be the formula of its Phosphate?
Answer:

1. The element lies in second group. So its valency is 2.
2. The formula of Phosphate is Ba₃(PO₄)₂ [since the valency of Phosphate is 3],

Question 38.
A, B, C are three elements having their atomic numbers equal to 2,10 and 5 respectively.
a) Which of these elements belong to same period?
b) Which of these elements belong to same group?
Answer:
The electronic configurations of A, B, C are as follows
A – 2, B – 2, 8, C – 2, 3.
a) So, B and C belong to same period because valence electron enters same orbit.
b) A and C belong to same group because both are noble gases.

Question 39.
Which element of 3^rd period will form a chloride of Cl₄?
Answer:
It would be Silicon because its electronic configuration is 2, 8, 4. So, it lies in third period and its valency is 4.

Question 40.
Which two elements of 3^rd period will form a covalent compound?
Answer:
The two elements are phosporous and chlorine.

Question 41.
An element has atomic number 12. State whether it is metal or non-metal. Why?
Answer:
Its electronic configuration is 2, 8, 2. It lies in 2^nd group. The elements towards left of periodic table are generally metals. So the element is metal.

Question 42.
Elements X, Y, and Z belong to IA group of the periodic table. Their atomic radii are as follows.
X → 1.33 Å,
Y → 0.95 Å,
Z → 0.60 Å.
Arrange the elements in the increasing order of atomic number by giving reason.
Answer:
As we move from top to bottom in a group, atomic size increases and atomic number also increases.
So the correct increasing order is Z, Y, X.

Question 43.
An element has an atomic number 16. State
i) period to which it belongs
ii) the number of valence electrons.
Answer:
Its electronic configuration is 2, 8, 6.
i) So it belongs to 3^rd period (orbit number).
ii) The number of valence electrons is 6.

Question 44.
Why is energy absorbed when electron is added to uni-negative ion?
Answer:
It is difficult to add an electron to uni-negative ion. In order to overcome the repulsion between the electrons, actually energy should be supplied to add another electron to uni-negative ion.

Question 45.
When do you observe liberation of energy?
Answer:
Atoms of some elements gain electrons while forming ionic compounds. An atom is able to gain electron when the electron is attracted by the nucleus. Attraction involves the liberation of energy.

Question 46.
Why does nitrogen have less electron affinity value compared to oxygen?
Answer:
The electron affinity of nitrogen is less than oxygen because of stable configuration of nitrogen (i.e., 2p³ configuration).

Question 47.
Which one between Na and Na⁺ would have more size? Why?
Answer:
Na has more size because when one electron is removed from Sodium atom the nucleus attraction over outermost electron increases so atomic size decreases.

Question 48.
Second ionization energy of an element is higher than its first ionization energy. Why?
Answer:
It is difficult to remove an electron from unipositive ion when compared with neutral atom. So second ionization energy is always greater than first ionization energy.

Question 49.
Hydrogen can be placed in group’1 and group 7 periodic table. Why?
Answer:
Hydrogen has both +1 as well as -1 oxidation states. So still there is some ambiguity in position of hydrogen.

Question 50.
Why do inert gases have zero valency value?
Answer:
Inert gases show zero valency because they do not take part in chemical reactions due to stable configuration.

Question 51.
Element ’Z’ belongs to (second) 2nd group in the periodical table. Write the formula of oxide.
Answer:
The formula of oxide of the element is ZO.

Question 52.
Do the atom of an element and its ion have same atomic size?
Answer:
No, generally cation has smaller size and anion has greater size.

Question 53.
The electronegativities of the elements in period 3 of the periodic table are as. follows.

Arrange the elements in which they occur in the periodic table from left to right.
Answer:
Na Mg Al Si P S Cl

10th Class Chemistry 9th Lesson Classification of Elements – The Periodic Table 2 Marks Important Questions and Answers

Question 1.
An element has atomic number 17. Where would you expect this element in the Periodic Table? Why? (AP June 2018)
Answer:

• Electronic configuration of the given element is 1s² 2s² 2p⁶ 3s² 3p⁵.
• So, it is in 3^rd period and 17^th group of periodic table.
• Due to the valency electronic configuration of 3s² 3p⁵ it belongs to 3^rd period and 17^th group.

Question 2.
How do you appreciate the special nature of inert gases?
Answer:
I appreciate the special nature of inert gases because it helps us in explaining the formation of chemical bonds among the atoms of elements and their stability.

Question 3.
The atomic number of an element is 35. Where would you expect the position of this element in the periodic table? Why? (TS June 2015)
Answer:

• The Electronic configuration of element with atomic number 35 is 2, 8, 18, 7.
• So it has seven valence electrons.
• That’s why it is present in 17^th group or VII A group and 4^th period.
• The element is Bromine.

Question 4.
Why were Dobereiner, Newlands and Mendeleeff not 100% successful in their classification of elements? Why is the modern table relatively a better classification? (TS March 2016)
Predict the reason.
Answer:

• All the known elements at the time of Dobereiner could not be arranged in the form of triads.
• Newlands’ periodic table was restricted only for 56 elements.
• As Mendeleeffs classification is based on atomic weight, his classification led to two defects like anomalous pair of elements and dissimilar elements placed together.
• Modern periodic table was prepared on the basis of atomic number. So the periods and groups are clearly defined.

Hence Dobereiner, Newlands, and Mendeleeffs classifications were not 100% successful, but modern classification is successful.

Question 5.
Observe the electronic configurations given below and write the group and period numbers of those elements. (TS March 2016)

Answer:
a) The period number is 3 and group number is 1.
b) The period number is 3 and group number is 15.

Question 6.
Observe the information provided in the table and answer the questions given below it. (TS June 2017)

i) What are the s-block elements in the table?
ii) What are the ‘p’ block and ‘d’ block elements in the table?
Answer:
i) s-block elements : Na, Ca

ii) p-block elements : C, P
d-block elements : Ti, Ni.

Question 7.
Imagine, which one in each of the following pairs is large in size relatively with other? Explain. (AP March 2019)
(X) Na, Al (Y) Na, Mg⁺²
Answer:
(X) 1. Na is large in size than Al.
2. Atomic size gradually decreases from left to right in a period.

(Y) 1. Na is large in size than Mg²⁺.
2. Na is larger than Mg and Mg is larger than Mg²⁺.

Question 8.
What are the limitations of Dobereiner triad?
Answer:

• All the known elements could not be arranged in the form of triads.
• The law failed for very low mass or for very high mass elements.
  Eg : In case of F, Cl, Br the atomic mass of Cl is not an arithmetic mean of atomic masses of F and Br.
• As the techniques improved for measuring atomic masses accurately, the law was unable to remain strictly valid.

Question 9.
Distinguish between electron affinity and electronegativity.
Answer:

Electron affinity	Electronegativity
1. It is the property of an isolated gaseous atom.	1. It is the property of a bonded atom.
2. It is the energy released and is measured in ev/atom or kJ/mole.	2. It is relative quantity and has no units.
3. It is the attraction of an atom for a single electron.	3. It is the attraction of an atom for a pair of electrons.

Question 10.
What is electronegativity? What are the various methods used to determine electronegativity? Explain.
Answer:
Electronegativity :
The electronegativity of an element is defined as the relative tendency of its atom to attract electrons towards itself when it is bounded to the atom of another elements.

Various methods to calculate Electronegativity :
1) Milliken Scale :
According to Milliken, the electronegativity of an element is the average value of its ionization energy and electron affinity.

2) Pauling Scale :
Pauling scale is based on bond energies. The electronegativity of hydrogen is assumed as 2.20. Electronegativity of other elements is calculated with respect to hydrogen.

Question 11.
Give the electronic configurations of following elements. What do say about these elements by writing their electronic configurations?
a) Na
b) Al
c) Sc
d) Ce
Answer:
a) Na : 1s² 2s² 2p⁶ 3s¹
b) M : 1s² 2s²2 2p⁶ 3s² 3p¹
c) Sc : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹
d) Ce : 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s² 4f²

Inference :
The valence electron enters different orbitals. So these elements belong to different blocks in modern periodic table, i.e. s, p, d, and f respectively.

Question 12.
Do you think that Newlands’ law of octaves is correct? Justify.
Answer:
No, Newlands’ law of octaves was restricted to only 56 elements and did not leave any room for new elements. Elements that were discovered later could not be filled into Newlands’ table in accordance with properties.

Question 13.
Why did Mendeleeff have to leave certine blank spaces in his periodic table?
Answer:
Mendeleeff predicted that some elements were missing in the table so he left blank spaces at the appropriate places in the table.

Question 14.
Give reason for the need of classification of elements.
Answer:
Classification is necessary because it is difficult to remember the properties of all the elements separately. It is easy to identify the properties of elements by making them groups with similar properties.

Question 15.
x, y, and z are the elements of a Dobereiner’s triad. If the atomic mass of ‘x’ is 7 and that of ‘z’ is 39, what should be the atomic mass of ‘y’?
Answer:
The atomic mass of x = 7 ;
The atomic mass of z = 39
x, y, z form Dobereiner triad
∴ Atomic mass oi y = average of x and z = \(\frac{7+39}{2}\) = \(\frac{46}{2}\) = 23

Question 16.
Name the two elements that would expect to have chemical properties similar to element with atomic number 11. What is the base for your choice?
Answer:
The element with atomic number 11 is sodium and its electronic configuration is 1s² 2s² 2p⁶ 3s¹ or 2, 8, 1.

So it has one valence electron, i.e. present in I group. We know that the elements present in same group have same valence electrons. So they show similar properties.

Therefore the other two elements are Lithium and Potassium.

Question 17.
An element X belongs to 3^rd period and group 14 of the periodic table. State
a) the number of valence electrons
b) the valency
c) the name of the element.
Answer:
a) The number of valence electrons are 4.
b) Its valency = 8 – 4 = 4.
c) The electronic configuration of element is 2, 8, 4.
(Because 3^rd period means third orbit, group 14 has 4 valence electrons). So, the element with atomic number 14 is Silicon.

Question 18.
Why is it easier to remove 4f electron than 4s?
Answer:
Orbitals belonging to the same main shell have different penetration power towards the nucleus. In fourth main shell the order of penetration is like this 4s > 4p > 4d > 4f. So, it is easier to remove 4f electron than 4s.

Question 19.
How is screening effect responsible for low ionization of cesium?
Answer:

• More the shells with electrons between the nuclear and the valence shell, they act as screens and decrease nuclear attraction over valence electron. This is called the screening effect.
• More the screening effect, less is the ionization energy.
• Cesium with more inner shells has less ionization energy.

Question 20.
Why does Boron have less ionization energy when compared with Beryllium?
Answer:

• The electronic configuration of Be and B are 1s² 2s² and 1s² 2p² 2p¹.
• The element Boron has less ionization energy due to less penetration power of 2p compared to 2s.

Question 21.
We know that as we move from left to right ionization energy increases. But ionization energy Nitrogen is more than Oxygen. Why?
Answer:

• It is easier to remove an electron from Oxygen when compared to Nitrogen.
• This is because Nitrogen has stable 1s² 2s² 2p³ electronic configuration which contains half filled 2p orbitals whereas Oxygen has 1s² 2s² 2p⁴ configuration.

Question 22.
Why is it difficult to remove an electron from Mg⁺ when compared with Mg?
Answer:

• The energy required to remove the first electron outermost orbit of a neutral gaseous atom of the element is called first ionization energy.
• The energy required to remove from unipositive ion of the element is called second ionization energy.
• Second ionization energy is always more than first ionization energy because it is difficult to move electron from unipositive ion due to greater nuclear attraction.
• So it is difficult to remove an electron from Mg⁺ when compared with Mg.

Question 23.
Using the periodic table predict formula of compound formed between an element ‘X’ of group 2 and another element of group 17.
Answer:

• The element X belongs to group 2. So, the number of valence electrons are 2 and its valency is 2.
• The element Y belongs to group 17 or VII. So, the number of valence electrons are 7 and its valency = 8 – 7= 1.

During formation compound elements exchange their valencies.
∴ The formula of compound is XY₂.

Question 24.
How do electronegativity values vary in period and group?
Answer:
Period :
When we move from left to right in period, the electronegativity increases due to decrease in atomic size.

Group:
When we move from top to bottom in a group, the electronegativity decreases due to increase in atomic size.

Question 25.
How does metallic and non-metallic characters vary in a period and group?
Answer:
Period:
When we move from left to right in a period, the metallic character decreases and non-metallic character increases.

Group :
When we move form top to bottom in a group, non-metallic character decreases and metallic character increases.

Question 26.
How do valency vary in period and group?
Answer:
Period :
When we move from left to right in a period, the valency does not follow a regular trend. For example, in second period the valency starts from 1 and increases to 4, then thereafter decreases to ‘O’.

Group :
When we move top to bottom in a group, the valency remains the same because in a group the valence electrons are same.

Question 27.
How does electron affinity vary in a period and group?
Answer:
Period :
When we move from left to right in period, electron affinity increases due to greater nuclear attraction over electron.

Group :
When we move from top to bottom, the electron affinity decreases in atomic size. As the size of the atom increases, the nuclear attraction over outermost electron decreases. So electron affinity decreases.

Question 28.
An element has atomic number 19. Where would you expect this element in the periodic table anti why?
Answer:
The electronic configuration of element is 1s²2s²2p⁶3s²3p⁶4s¹. So the element is in 4^th period and I group.

Question 29.
The electronic configuration of the element X, Y, and Z are given below,
a) X = 2, 5
b) Y = 2, 8, 1
c) Z = 2, 8
i) Which element belongs to 18^th group?
ii) Which element belongs to 15^th or V group?
iii) Which element belongs to third period?
Answer:
i) Z belongs to 18^th group because it is a noble gase (i.e. Ne).
ii) X belongs to 15^th or V group because it has 5 valence electrons.
iii) Y belongs to 3^rd period because the valence electron is present in 3^rd orbit.

Question 30.
Referring the part of periodic table given below answer the questions that follow.

1) What happens to the atomic size if moved from left to right? Support your answer.
2) What changes do you observe in the metallic properties of the elements when moved from left to right?
Answer:
1) When we move from left to right in a periodic table atomic radii of elements decrease, as a result the size of the,atom decreases,

2) When we move from left to right in a periodic table electronegativity values of elements increase, as a result the metallic properties of the elements decrease.

Question 31.
State the name of element, number of valence electrons, valency, the group number and the period number of each element given in the following table.

Answer:

10th Class Chemistry 9th Lesson Classification of Elements- The Periodic Table 4 Marks Important Questions and Answers

Question 1.
What is Ionization Energy? Explain the factors that effect Ionization Energy. (AP June 2017)
(OR)
What is ionization energy? What are the factors which influence ionization energy? Explain.
(OR)
Write the factors that influence ionization energy and explain any three of them. (TS March 2019)
Answer:
Ionization energy :
The energy required to remove an electron from the outermost orbit or shell of a neutral gaseous atom is called ionization energy.
Factors influencing ionization energy :
1) Nuclear charge :
As nuclear charge increases, ionization energy increases.

2) Screening effect or shielding effect:
More the screening effect, less is the ionization energy.

3) Penetrating power of the orbitals :
If the orbitals have less penetrating power, then the ionisation energy is less. Generally, the penetrating power of orbits are like this : s > p > d > f.

4) Stable configuration :
The elements having half-filled or completely filled orbitals have more stability. So the ionization energy is more when the element has stable configuration.

5) Atomic size :
As the atomic size increases, the nucleus attraction over outermost electron decreases. So ionization energy decreases.

Question 2.
Elements of one short period of the Periodic Table are given below in the order from left to right. (AP March 2017)
Li, Be, B, C, N, F, Ne
Answer the following:
(i) To which period, do these elements belong?
(ii) One element of this period is missing. Which is the missing element and where it should be placed?
(iii) Which of the above elements belong to the family of halogens? What is its electronegativity value?
(iv) How does the metallic character varies in the Period?
Answer:
(i) 2nd period.
(ii) Oxygen.
It should be placed between Nitrogen and Flourine.

(iii) Flourine
Electro negativity 4.0

(iv) Decreases from left to right.

Question 3.
In the table given below, names of some elements of families are given. Based on this, fill the information in the empty boxes. (TS June 2015)

Answer:

Question 4.
Two elements X and Y belong to Groups 1 and 2 respectively in the same period of the Periodic Table. Compare these elements with respect to : (TS March 2015)
i) number of electrons in their outermost orbit.
Answer:
The number of electrons in the outermost orbit of element X = 1
The number of electrons in the outermost orbit of element Y = 2

ii) their atomic size and their valencies.
Answer:
The atomic size of the Y is lesser than X
Valence of X = 1 ; Valence of Y = 2

iii) their ionisation energy and metallic character.
Answer:
The ionization energy of Y is greater than X, X has higher metallic character than Y.

iv) formulae of their chlorides and sulphates.
Answer:
Chloride of X …. XCl
Chloride of Y …. YCl₂
Sulphate of X …. X₂SO₄
Sulphate of Y …. YSO₄

Question 5.
How are the elements arranged into groups and periods in the Modern Periodic Table? Elements in a group possess similar properties, but elements in a period do not show similarities in their properties. Why? (TS June 2017)
Answer:

• The Modern periodic table is arranged in groups and periods based on the electronic configuration of the atoms of elements.
• Physical and Chemical Properties of elements are related to their electronic con-figurations particularly the outershell configurations.
• The atoms of the elements in a group posses similar electronic configurations.
• The elements in a group should have similar chemical properties and there should be regular gradation in their physical properties from top to bottom.
• Across the table from left to right in any period, elements gets an increase in the atomic number by 1 unit between any two successive elements.
• Therefore the electronic configuration of valence shell of any two elements in a given period is not same.
• Due to this reason elements along a period posses different chemical properties with regular gradation in their physical properties from left to right.

Question 6.
Explain any four factors which influence the electron affinity (Electron Gain Enthalpy). (TS March 2017)
Answer:
Factors effecting of electron affinity
1. Nuclear Charge :
If nuclear charge increases electron affinity increases, similarly it decreases if nuclear charge decreases.

2. Screening effect:
If screening effect value increases electron affinity increases, if it decreases electron affinity decreases.

3. Penetration power of the orbitals :
If penetration power of the orbitals increases electron affinity increases. If it decreases electron affinity decreases.

4. Stable configuration :
If an atom has stable electron configuration electron affinity will decreases.

5. Atomic radius :
If atomic radius increases electronic affinity will be increases. If atomic radius decreases electron affinity decreases.

6. Metallic property :
If metallic property increases electron affinity decreases.

7. Non-Metallic property :
Non-Metallic property increases electron affinity value increases.

Question 7.
Observe the information and answer the following questions. (TS June 2018)

Name of the Element	Atomic Number	Electronic Configuration
Sodium	11	[Ne] 3s1
Magnesium	12	[Ne] 3s2
Potassium	19	[Ar] 4s1
Calcium	20	[Ar] 4s2

1) What is valency of Magnesium?
Answer:
Valency of magnesium is two.

2) Which element has more electro-positivity?
Answer:
Potassium (K) has more electro-positivity.

3) Write the elements which belongs to (third) 3^rd Period.
Answer:
The elements which belongs to 3^rd period are Sodium (Na), Magnesium (Mg).

4) Write the elements which belongs to 1^st Group.
Answer:
Sodium (Na), Potassium (K) belong to 1^st Group.

Question 8.

Answer the following from the above in brmation. (TS March 2018)
i) Which element posses the higher atomic radius in the above table?
Answer:
The element having higher atomic radius is ‘K’ (Potassium)

ii) Mention two plair of element which forms ionic bond.
Answer:
Na, Cl Mg, CL

iii) Name the two elements having valency 2.
Answer:
Elements having valency 2 are Be, Mg, Ca, 0, S, Se.

iv) Which element has electronic configuration of 1s² 2s² 2p⁴.
Answer:
Oxygen.

Question 9.
Explain the significance of three quantum numbers in predicting the position of an electron in an atom. (AP SCERT: 2019-20)
Answer:
Each electron in an atom is described by a set of three quantum numbers n, 1 and ml.
1. Principal quantum number (n):
The principal quantum number is used to describe the size and energy of the main shell. It is denoted by ‘n’. ‘n’ has positive integer values of 1, 2, 3, It is used to know the number of orbitals (n²) and electrons in an orbit. (2n²).

As ‘n’ increases the shells becomes larger and the electrons in those shells are farther from the nucleus and their energies increases.

2. The angular – momentum quantum number (l) :
‘l’ has integer values from O’ to n – 1, for each value of ‘n’. Each ‘l’ value represents one sub-shell. It is used to describe the shape of an orbit.

3. The magnetic quantum number (m_l) :
The magnetic quantum number (m_l) has integer values between -l and +l including zero.

If l = 0, the possible ml value is 1.
l = 1, the possible ml value is -1, 0 and 1.
Thus for a certain value of 1, there are (2l + 1) integer values of ml.

These values describe the orientation of the orbital in space relative to the other orbitals in the atom.

Ex: When l = 1, (2l + 1) = 3, that means ml has 3 values namely -1, 0, 1 or three p orbitals, with different orientations along x, y, z axes, labelled as p_x, p_y and p_z orbitals.

Predicting the position of an electron in an atom :
If the values of n, l, and ml are 2, 1,-1 respectively the electron is present in 2px orbital in L – shell.

Question 10.
Answer the following question based on the values of the atomic radii of the elements of one of the periods in modern periodic table (AP SCERT: 2019-20)
Li (152), Be (111), B (88), C (77), N (74), O (66) and F (64)
a) What is the trend of atomic radii of given elements?
b) In the numerical listing of periods in the modern periodic table, what number was given to above elements?
c) Mention the unit of atomic radius.
d) Why the values of atomic radius varied along the period?
Answer:
a) Atomic radii of elements decrease while going left to right in the periodic table.

b) Period – 2
c) Unit of atomic radius is ‘pm’ (picometer).
d) There should be no change in distance between nucleus and outer most shell for the elements in one period.

But, nuclear charge increases because of the increase in the atomic number of elements in a period.

Hence, the nuclear attraction on the outer shell electrons increases.

As a result the size of the atoms decreases while going left to right in a period.

Question 10.
Mendeleeff classified the then known 63 elements in the form of a periodic table. Mention any two things that benefitted study of chemistry, to support the above statement.
Answer:

• Mendeleeff accepted minor inversions in the order of increasing atomic weights as these inversions resulted in elements being placed in the correct group.
• It was the extraordinary thinking of Mendeleeff that made the chemists to accept the periodic table and recognise Mendeleeff more than anyone else as the originator of the periodic law.
• At the time when Mendeleeff introduced his periodic table even electrons were not discovered.
• Even then the periodic table was prepared to provide a scientific base for the study of chemistry of elements.
• In his honour the 101 element was named “Mendelevium”.

Question 11.
How do these properties vary in period and group?
1) Valency
2) Atomic radius
3) Ionisation energy
4) Electron affinity
5) Electronegativity
6) Electropositivity
7) Metallic nature
8) Non-Metallic nature.
Answer:

Question 12.
Explain the salient features and achievements of the Mendeleeffs periodic table.
Answer:
Mendeleeffs periodic table is based on atomic weight.
1) Periodic law:
The physical and chemical properties of the elements are the periodic functions of their atomic weights.

2) Groups and sub-groups :
The vertical columns in Mendeleeffs periodic table are called groups. There are eight groups and elements in each group have similar properties. Each group is divided into sub-groups A and B.

3) Periods :
The horizontal rows are called periods. There are ‘seven’ periods in Mendeleeffs periodic table.

4) Predicting the properties of missing elements :
Based on the arrangement of elements in table, Mendeleeff predicted that some elements were missing and left blank spaces at appropriate places in the table. Later they were discovered.

5) Correction of atomic weight :
It is useful in correcting atomic weights of elements.

6) Anomalous series :
More atomic weight element like Tellurium (Ti) is placed before the less atomic weight element like Iodine in order to place these elements in the correct group.

Question 13.
How does atomic radius vary la period and group? Explain.
Answer:
Period :

1. As we move from left to right the atomic radius decreases because the electrons enter the same main shell.
2. The nuclear charge increases because of increase in atomic number of elements in period.
3. Hence, the nuclear attraction on the outer shell electron increases. As a result, the size of atom decreases.

Group:

1. Atomic radius increases from top to bottom in a group of the periodic table.
2. As we go down in a group, the atomic number of element increases. In order to accommodate more number of electrons, there are more additional shells.
3. As a result, the distance between the nucleus and the outer shell of atom increases.
4. So atomic size increases.

Question 14.
What is electron affinity? What are the factors which influence electron affinity?
Answer:
Electron affinity :

1. The electron affinity of an element is defined as the energy liberated when an electron is added to its neutral gaseous atom.
2. Electron affinity of an element is also called electron gain enthalpy of that element.
3. M_(g) + e^– → M^–_(g) + EA₁ (M = Atom of element, EA₁ = First Electron affinity)
   M^–_(g) + e^– → M^-2_(g) + EA₂ (EA₂ = Second Electron affinity)

Factors influencing Electron affinity :
1) Nuclear charge :
Greater the nuclear charge, greater the electron affinity value because of greater attraction for incoming electron.

2) Atomic size :
As the atomic size increases, the attractive force of the nucleus on the electron decreases. So electron affinity decreases.

3) Electronic configuration :
The elements having stable electronic configurations of half filled or completely filled valence sub-shells show very small tendency to accept additional electron. So the electron affinity is low or almost zero for these elements.

4) Penetrating power of the orbitals :
As the penetrating power of the orbitals increases, the electron affinity increases.

5) Screening effect or shielding effect:
More the screening effect of orbitals, less is the electron affinity value.

Question 15.
How did Mendeleeff correct atomic weights of various elements?
Answer:

• Atomic weight = Equivalent weight x Valency
• By using the formula, the atomic weight of Beryllium was calculated as 13.5 (Equivalent weight of Be = 4.5, valency = 3)
• With this atomic weight the element should be placed in wrong group.
• So Mendeleeff predicted its valency is only 2. From that he calculated the atomic weight of Beryllium as 9.
• Now it fitted into correct group.
• Similarly, Mendeleeff corrected atomic weights of Indium and Gold.

Question 16.
Answer the following questions if atomic number of element is 15.
1) What is the name of the element?
2) What is the electronic configuration of element?
3) Which period and group does it belong to?
4) How many valence electrons are there in the element?
5) What is the valency of the element?
Answer:

1. The element is phosporous,
2. The electronic configuration of element is 1s² 2s² 2p⁶ 3s² 3p³ or 2, 8, 5.
3. It belongs to 3^rd period (orbit number is 3) and V or 15 group (Number of electrons in valence orbit is 5.)
4. Number of valence electrons are 5.
5. Its valency is 8 – 5 = 3.

Question 17.
If an element belongs to 3^rd period and 17^th group, then answer the following questions.
1) What is its electronic configuration?
2) How many valence electrons are there in the element?
3) What is the valency of element?
4) What is atomic number of element?
5) What is the name of the element?
6) Give two more elements which have similar properties as this element?
Answer:

• The element belongs to 3rd period and 17^th group. So the valence orbit is 3^rd and number of valence electrons in that orbit is 7. So its electron configuration is 2, 8, 7.
• The number of valence electrons are 7.
• The valency of element = 8 – 7 = 1.
• The atomic number of element is 17.
• Name of the element is chlorine.
• Chlorine belongs to Halogen family. So Fluorine, Bromine, Iodine, and Astatine have similar properties as chlorine.

Question 18.
The elements of a periodic table are given below in the order from left to right.
Li Be B C O F Ne
1) To which period do these elements belong?
2) One element of this period is missing. Which is the missing element and where should it be placed?
3) Which one of the elements in this period shows the property of catenation?
4) Place the three elements fluorine, beryllium, and oxygen in the order of increasing electronegativity.
5) Which one of the above elements belongs to halogen series?
Answer:

1. The elements belong to 2^nd period.
2. The element which is missing is Nitrogen which is placed in between carbon and oxygen.
3. Carbon shows the property of catenation.
4. The ascending order of electronegativity for these element is Beryllium < Oxygen < Fluorine.
5. Fluorine belongs to halogen family.

Question 19.
A group of elements in periodic table is given below.
Boron, Aluminium, Gallium, Indium, and Thallium.
(Boron is the first element and Thallium is the last element)
Answer the following questions in relation to the above group of elements.
1) Which element has the most metallic character?
2) Which element would be expected to have the highest electronegativity?
3) If the electronic configuration of Aluminium is 2, 8, 3, how many electrons are there in outer shell of thallium?
4) The atomic number of Boron is 5. Write the chemical formula of the compound formed when Boron reacts with Chlorine.
5) Do the elements in the group to the right of this Boron group have more metallic or less metallic character? Justify your answer.
Answer:
1) Thallium has the most metallic character because as we move from top to bottom in a group the metallic character increases.

2) Boron has the highest electronegativity because as we move from top to bottom in a group electronegativity decreases.

3) Thallium is in the same group as Boron. So, the number of electrons in outermost shell of Thallium is 3.

4) The atomic number of Boron is 5. So, its electronic configuration is 2, 3. Therefore its valency is 3.

Whereas the atomic number of Chlorine is 17. So, its electronic configuration is 2, 8, 7. Therefore its valency is 1.

The formula of compound formed between Boron and Chlorine is BCl₃.

5) The elements in the group right to Boron group have lesser metallic character because as we move from left to right in a period metallic character decreases.

Question 20.
The following questions refer to the periodic table.
1) Name the first and the last element in period 2.
2) What happens to the atomic size of elements moving from top to bottom of a group?
3) Which of the elements has the highest electron affinity among the halogens?
4) What is common feature of the electronic configurations of the elements in group 16?
Answer:
1) The first and the last elements of 2^nd period or Lithium and Neon.

2) The atomic size decreases as we move from top to bottom in a group because there is an addition of shell each time as we move down the group.

3) Chlorine has the highest electron affinity. We know as move from top to bottom the electron affinity values decrease. But due to small size of fluorine there would be more electron-electron repulsions, if we add electron. So Chlorine has more electron affinity.

4) All these have same general outermost electronic configuration that is ns² np⁴.

Question 21.
Answer the following.
1) Elements of which groups have low ionization energy?
2) What is your guess about atomic size of an element with seven electrons among all the elements in the same period?
3) Which element has the highest electronegativity? Why?
4) Which element has the highest electropositivity? Why?
Answer:
1) Group IA, IIA elements have lower ionization energy values because they have metallic character.

2) As we move from left to right in a period atomic size decreases. So element with seven outermost electrons has least size among all the elements in the same period.

3) Fluorine has the highest electronegativity because when we move from left to right in a period atomic size decreases and electronegativity values increase. So Fluorine has the highest electronegativity.

4) Cesium has the highest electropositivity or positive character because when we move from top to bottom in a group atomic size decreases. So electropositive character increases. Therefore Cesium has the highest electropositive character.

Question 22.
Given below is the electronic configuration of A, B, C, D.

A) 1s2 2s2 2p¹	a) Which are the elements coming within the same period?
B) 1s2 2s2 2p6	b) Which are the elements coming within the same group?
C) 1s2 2s2 2p6 3s2 3p6	c) Which are the noble gas elements?
D) 1s2	d) Which group and period does the element C belong to?

Answer:
a) A and B belong to same period because the valence electrons of both the elements lie in the same orbit.
b) Elements A and C and elements B and D.
c) B and D are noble gas elements.
d) C belongs to 3^rd period (orbit number) and III group (Number of valence electrons).

Question 23.
Write down the characteristics of the element having atomic number 16.
i) Electronic configuration
ii) Period number
iii) Group number
iv) Element family
v) Number of valence electrons
vi) Valency
vii) Metal or non-metal
viii) Name of the element
Answer:
i) Electronic configuration of element is 1s² 2s² 2p⁶ 3s² 3p⁴ or 2, 8, 6.
ii) Period number is 3 because valence electron lies in 3^rd orbit.
iii) Group number is 6 because the number of valence electrons are 6.
iv) Element belongs to chalcogen family.
v) Number of valence electrons are 6.
vi) Valency = 8 – 6 = 2.
vii) It is a non-metal because in a period when we move from left to right non-metallic character increases.
viii) Name of the element is sulphur.

Question 24.
The second period element ‘F has electron gain enthalpy than the third period elements of same group ‘Cl’. Why?
Answer:

• In a group of elements, the electron gain enthalpy decreases from top to bottom.
• But in general the second element in a group, i.e. 3^rd period element has greater electron gain enthalpy than the first element, i.e. 2^nd period element.
  Ex : E.A of F < E.A of Cl.
• This is because Fluorine atom is smaller in size than Chlorine atom.
• F₂ also has strong inter electronic repulsions.
• In the addition of an electron to fluorine atom, the electronic repulsions overcome at the expense of a part of the energy liberated.

Hence the overall energy liberated is less than that of Chlorine atom.

Question 25.
Differentiate the metals and non-metals.
Answer:

Metals	Non-Metals
1. Metals have lustrous surface.	1. Non-metals do not have lustrous surface.
2. They show malleability.	2. They do not show malleability.
3. They show ductility.	3. They do not show ductility.
4. They produce sonorous sound.	4. They do not produce sonorous sound.
5. Generally they are hard.	5. Generally they are soft.
6. They are good conductors of electricity.	6. They are bad conductors of electricity.
7. Generally they liberate hydrogen gas when they are treated with acids.	7. They do not liberate hydrogen gas.

Question 26.
The electronic configuration of atom A is 2, 8, 6.
a) What is the atomic number of element A?
b) State whether the atomic size of element A is bigger or smaller than the atom having atomic number 14. Why?
c) Which of the elements exhibits similarity in chemical properties as element A 0(8), C(6), N(7), AV(18). Why?
d) How does the element form inert gas configuration?
Answer:
The electronic configuration of atom – A is 2, 8, 6.
a) Atomic number of element ‘A’ is 16, i.e. Sulphur.

b) The atom which has atomic number – 14 is Silicon (Si).

Atomic size of element decreases across period from left to right. So the atomic size of element ‘A’ is smaller than the atom having atomic number 14.

c) Element oxygen O₈ – exhibits similarity in chemical properties as element A, because they belong to the same group.

d) Given element – A becomes inert gas, i.e. Argon configuration by gaining ‘2’ electrons.

Question 27.
Select the correct answers from the choices A, B, C, D which are given with reference to the variation of properties in the periodic table. Which of the following is generally true?
A : Atomic size increases from left to right across a period.
B : Ionisation energy increases from left to right across a period.
C : Electropositive character increases going down a group.
D : Electronegativity increases going down a group.
Answer:
1) A is wrong because when we move from left to right the atomic number increases. So, the nuclear attraction over outermost orbital increases. Therefore the atomic size decreases.

2) B is correct but it does not follow a regular trend in a period.

3) C is correct. As move from top to bottom in a group atomic size increases. Therefore it is easy to lose electrons. So electropositive character increases.

4) D is wrong because as we move from top to bottom in a group atomic size increases. So electronegativity decreases.

Question 28.
Some elements belonging to second period of periodic table, and their atomic radii are given below. Observe them and write answers.

1) Write the elements in the ascending order of their atomic radii.
2) Which of the 2nd period elements closer to the configuration of inert gas?
3) Which is the outermost orbit of all these elements?
4) Which element’s atomic size is bigger, Beryllium or Carbon? Why?
Answer:

1. The ascending order of atomic sizes is O, N, C, B, Be and Li.
2. Lithium has closest inert gas configuration, i.e. 1s² 2s¹. Its nearest inert gas is Helium.
3. The outermost orbit for all these elements is second orbit.
4. Beryllium has more atomic size than Carbon. Because when we move across a period the atomic number increases. So nuclear attraction over outermost orbit increases and atomic size decreases. So carbon has lesser size than Beryllium.

Question 29.

Refer the above part of periodic table and answer the following questions.
a) Element with the least atomic size.
b) Write the electronic configuration of the elements B and E.
c) Identify the elements that have similar physical and chemical properties as the element Y.
d) Arranged elements increasing order of their electronegativity values.
Answer:
a) The element with least atomic size is E. Because when we move from left to right in a period the atomic size decreases,

b) Electronic configuration of B is 1s² 2s² 2p⁶ 3s² 3p¹ Because the element belongs to 13th group its general configuration is ns² np¹ and the element belongs to third period and its atomic number is 13. Similarly electronic configuration of E is 1s² 2s² 2p⁶ 3s² 3p¹. Because the element belongs to 16th group. Its general configuration is ns2np4 and it is in third period. So its atomic number is 16.

c) The elements which have similar physical and chemical properties with Y are X and Z. Because they lie in a single group, i.e. 1st group. In a group, elements are having similar physical and chemical properties.
d) Z < Y < X < B < C < D < E.

Question 30.
Consider the section of the periodic table given below.

1) Which is the most electronegative?
2) How many valence electrons are present in G?
3) Write the formula of the compound between B and H.
4) Which element has similar properties as J?
5) Which element has greater size-either D or E?
Answer:

1. J is the most electronegative. In a period electronegative values increase.
2. G is present in V group. So the number of valence electrons is 5.
3. B is present in first group. So its valency is 1 and hydrogen also has valency 1. Therefore the compound is BH.
4. K lies in same group as J. Elements belonging to same group have similar properties. So, K has similar properties as J.
5. E has greater size because as we move from top to bottom the atomic size increases.

These AP 9th Class Social Studies Important Questions 15th Lesson Industrialisation and Social Change will help students prepare well for the exams.

AP State Syllabus 9th Class Social 15th Lesson Important Questions and Answers Industrialisation and Social Change

9th Class Social 15th Lesson Industrialisation and Social Change 1 Mark Important Questions and Answers

Question 1.
In what way did Canal Transportation aid Industrial Revolution? (SA-I : 2019-20)
Answer:
Canals were the answer to moving heavy objects to large distances

9th Class Social 15th Lesson Industrialisation and Social Change 2 Marks Important Questions and Answers

Question 2.
Why did modem industrialisatfon first occured in Britain only? (SA-III : 2016-17)
(OR)
Why do you think Britain was the first country to Industrialize?
Answer:

• Britain was blessed with modest climate to suit cotton industry.
• There was no scarcity of power.
• There was availability of sufficient raw material.
• Coal and Iron were available in abundance side by side.
• It was convenient to transport the raw material by water.
• There was no dearth of capital and Bank of England was also helpful in raising capital.
• Workers were available in large numbers.
• It was ready to sea trade with a large number of ports.

Question 2.
20th century inventions were hugely influenced by major developments in technology and resources, enabling the inventions of key items and devices which changed the way we live today.
Mention any two inventions one each in transportation and medicine and mention briefly how they changed the way we live today. (SA-II : 2018-19)
Answer:
Transportation :
Aeroplanes, Motor vehicles, Railways, etc.

Medicine:
Anti-biotics, vaccines, chloroforms, Anti-virus, etc. Now-a-days world become a big village by a fastest means of transport. Even long distance also reached in a short time. Due to medicines, the life expectancy of human being is increased.

9th Class Social 15th Lesson Industrialisation and Social Change 4 Marks Important Questions and Answers

Question 1.
The road-builder John Metacalf, who personally surveyed surfaces for roads and planned them, was blind. The canal builder James Brindley was almost illiterate, with such poor spelling that he could never spell the word ‘navigation’, but he had tremendous powers of memory, imagination and concentration.
Read the paragraph given above and comment on that. (SA-III : 2016-17)
Answer:
According to the above para, if we want to invent a new thing we need more determination, interest, curiosity, even luck, than the application of scientific knowledge. Along with the above, memory, imagination, and concentration also need.

Question 2.
“Good transportation facilities leads to rapid industrialization” – Justify the statement. (SA-I : 2018-19)
Answer:

• Transport system really helps the industry.
• Without transportation, the products made by the industry cannot be sold in distant places.
• The industry has a particular transport system to send their products to places and sell them for profit.
• Without proper transport system, there is risk of damage of products.
• The invention of steam engine reduced the cost of transportation.
• Development of aircraft was useful for fastest means of transport.
• Good transport system leads to rapid industrialization.

Question 3.
Mobile phone – Internet – Computers – Airways
Choose any TWO of the inventions listed above Explain how they changed people’s lives. (SA-I : 2019-20)
Answer:
Mobile Phone:

• Mobile phones have completely changed the way people interact.
• Today, the mobile phone has become part and parcel of many people’s lives.
• You can call, send text messages, read emails, play games as well as read and edit documents.
• Through mobile phone, we can send money quickly to others who are in need.
• It create new market places.
• It help people find jobs.
• It help the farmers to get weather information.

Internet:

• The Internet creates new ways for us to communicate, work and share information.
• The main advantage of the internet is it ability to connect billions of computers and devices to each other.
• By it, we get more information.
• Enjoy virtual field trips.
• It creates assignment convenience and flexibility.

Computer:

• It act as highly reliable scientific equipment.
• They receive and store data and carries out logical and mathematical calculations too to provide fast and accurate results.
• It can store more data.

Airways :

• Through air ways we can reach our destination quickly.
• It transports people, goods, the military equipment around the world.
• It is the fastest means of transport.
• During the time of floods and calamities we can use more airways only to reach the place.
• It is supported to go to remote areas.
• It creates convenience to passengers.

Question 4.
Explain how the condition of the workers steadily declined in the early twentieth century Europe. (SA-I : 2019-20)
Answer:
Conditions of the worker.
1. The aboudance of labour in the market affected.

2. Seasonality of work :
It meant prolonged periods without work.

3. Low Real wages :
Wages are very low.

4. Poverty and Unemployment:
At the mid of 19th century, about 10 percent of Urban population was extremely poor.

The Unemployment rate was very high.

9th Class Social 15th Lesson Industrialisation and Social Change Important Questions and Answers

Question 1.
What is called ‘First Industrial Revolution?
Answer:
The transformation of industry and the economy in Britain between the 1780s and the 1850s is called the “First Industrial Revolution.”

Question 2.
Who used the term ‘Industrial Revolution’?
Answer:
The term ‘Industrial Revolution’ was used by European scholars – Georges Michelet in France and Friedrich Engels in Germany. It was used for the first time in English by the philosopher and economist Arnold Toynbee (1852-83), to describe the changes that occurred in British industrial development between 1760 and 1820.

Question 3.
What were the two main features of cotton industry?
Answer:
From the 1780s, the cotton industry symbolised British industrialisation in many ways. This industry had two features which were also seen in other industries. Raw cotton had to be entirely imported and a large part of the finished cloth was exported to other countries. Britain had its control over the sources of raw cotton as well as the markets. Where they sold cloth. This helped to increase its control over the colonies.

Question 4.
What was the new power source in England?
Answer:
Steam

Question 5.
Which country experienced modern industrialisation for the first time?
Answer:
Britain experienced modern industrialisation for the first time.

Question 6.
Name any bank in England.
Answer:
The Bank of England.

Question 7.
Who were used in coal mines to reach deep coal faces?
Answer:
Children were used in coal mines to reach deep coal faces.

Question 8.
Which countries lacked colonial resources?
Answer:
Germany and France lacked colonial resources.

Question 9.
What is Industrial revolution? Who coined this name?
Answer:

• The economy and industries in Britain changed completely between 1780s and 1850s.
• This phase is known as ‘First Industrial Revolution’.
• The term ‘Industrial Revolution’ was used by European Scholars George Michelet in France and Fredrich Engels in Germany.
• It was used for the first time in English by the Philosopher and economist Arnold Tonybee.

Question 10.
What do you know about the picture?

Answer:
This was the Cast Iron Bridge. It was near Coalbrookdale. It was designed by the third Darby.

Question 11.
What was it? How did it look like?

Answer:
This was James Watt’s steam engine. It was just looking like our present day tractor.

Question 12.
Compare the effects of the coming of the railways in different countries in the world.
Answer:

• The first steam locomotive, Stephenson’s Rocket, appeared in 1814. Railways emerged as a new means of transportation that was available throughout the year, both cheap and fast, to carry passengers and goods.
• They combined two inventions, the iron track which replaced the wooden track in the 1760s, and haulage along it by steam engine.
• The invention of the railways took the entire process of industrialisation to a second stage.
• The first railway line connected the cities of Stockton and Darlington in 1825, a distance of 9 miles that was completed in two hours at speeds of up to 24 kph (15 mph).
• The next railway line connected Liverpool and Manchester in 1830. Within 20 years, speeds of 30 to 50 miles an hour were usual.

Britain :
The railways changed British Society in numerous ways. It is nonetheless clear that the railways had a sizeable impact in many spheres of economic activity and daily life of the people.

Canada :
In Canada, the national government strongly supported railway construction for political goals.

India :
India provides an example of the British empire pouring its money into a very well built system designed for military reasons and with the hope that it would stimulate industry. The system was over built and much too elaborate and expensive for the small amount of freight traffic it carried.

Belgium :
Belgium took the lead in Industrial revolution on the continent starting in the 1820s. It provided an ideal model for showing the value of the railways for speeding the industrial revolution.

France:
In France, railways became a national medium for the modernisation of backward regions. Although starting the whole system at once was politically expedient, it delayed completion and forced even more reliance and temporary experts brought in from Britain.

Germany:
The take-off stage of economic development came with the railroad revolution in the 1840s. As a means of national defence, it facilitates the concentration, distributional direction of the army. It is a means to the improvement of the culture of the nation.

Russians:
It was Americans who brought the technology of railway construction to Russia in 1842. Russia was in need of big transportation system and geographically suited to railroads.

Thus the railways in different countries helped the industrial revolution in transportation.

Question 13.
Read the following passages and answer the given questions.

The Krupp Family

The Krupp family established what was going to become the world’s largest arms factory. This first factory specialised in field gun manufacture and, by 1887, it supplied arms to forty six different countries.

During World War I the Krupp factories made guns for the German artillery.

The Krupps supported Hitler in the German general election of 1933. As Nazi Germany occupied neighbouring countries, Alfred Krupp seized new land to make more factories. Many of these factories used slave-labour from the Nazi concentration camps.

1) What was the name of the family?
Answer:
The ’Krupp’ family.

2) What was the first factory?
Answer:
Gun manufacturing factory.

3) Which World War was mentioned here?
Answer:
First World War.

4) Whom did the Krupps support?
Answer:
The Krupps supported Hitler in the German general election of 1933.

5) Who were the workers in the factories?
Answer:
The slave – labour from the Nazi concentration camps.

Question 14.
Read the following passages and answer the given questions.
Steam power was first used in mining industries. As the demand for coal and metals expanded, efforts to obtain them from ever-deeper mines intensified. Flooding in mines was a serious problem and steam engines were used to drain the mines. But the technology was still very imperfect to be used on a large scale.

James Watt’s (1736-1819) invention converted the steam engine from being a mere pump into a ‘prime mover’ capable of providing energy to power machines in factories. Backed by the wealthy manufacturer Matthew Boulton (1728-1809), Watt created the Soho Foundry in Birmingham in 1775. From this foundry James Watt’s steam engines were produced in steadily growing numbers. By the end of the eighteenth century, Watt’s steam engine was beginning to replace hydraulic power. In 1840, British steam engines were generating more than 70 per cent of all European power.
1) Which power was first used in mining industries?
Answer:
Steam power

2) What was a serious problem?
Answer:
Flooding in mines was a serious problem.

3) Who was the wealthy manufacturer?
Answer:
Matthew Boulton.

4) In which foundry were the Watt’s engines produced?
Answer:
In Soho Foundry in Birmingham.

5) Appreciate the British steam engines.
Answer:
In 1840, British steam engines were generating more than 70% of all European power.

Question 15.
Read the following passages and answer the given questions.
Transportation
The need to transport raw materials and manufactured products led to the improvement of roads and the digging of canals in England. Me Adam devised the method of making ‘pakka’ or ‘macadamamised’ roads.

Canals were initially built to transport coal to cities. This was because the bulk and v/eight of coal made its transport by road much slower and more expensive than by barges on canals. The demand for coal, as industrial energy and for heating and lighting homes in cities, grew constantly. The making of the first English canal, the Worsley Canal (1761) by James Brindley (1716-72), had no other purpose than to carry coal from the coal deposits at Worsley (near Manchester) to that city. After the canal was completed the price of coal fell by half. Thousands of kilometres of canals were built by 1830 and were used to transport commodities cheaply. They were mostly built by landowners to enhance the value of their properties.
1) Which led to the improvement of roads and the digging of canals in England?
Answer:
The need to transport raw materials and manufactured products led to the improvement of roads and the digging of canals in England.

2) Which were initially built?
Answer:
Canals were initially built to transport.

3) Which grew constantly?
Answer:
The demand for coal, as industrial energy and for heating and lighting homes in cities, grew constantly.

4) What is the name of first English canal?
Answer:
Worsley Canal.

5) What was the interest of land owners in building the first canal?
Answer:
They were interested in enhancing the values of their properties.

6) Who built this canal?
Answer:
James Brindley.

Question 16.
Observe the following picture and answer the given questions.

Woman in gilt-button factory, Birmingham. In the 1850s, two thirds of the workforce in the button trade was women and children. Men received 25 shillings a week, women 7 shillings and children one shilling each, for the same hours of work.
1) Who was she?
Answer:
She was a woman in gilt-button factory.

2) Where was the factory?
Answer:
It was in Birmingham.

3) Which year did the picture belonged to?
Answer:
It belonged to the 1850s.

4) What were the earnings of the workers?
Answer:
Men – 25 shillings a week
Women – 07 shillings a week
Children – 01 shilling a week

5) Is there any difference in the working time?
A. No, it was equal to all.

Question 17.
Read the following passages and answer the questions given below.

The Workers

A survey in 1842 revealed that the average lifespan of workers was lower than that of any other social group in cities: it was 15 years in Birmingham, 17 in Manchester, 21 in Derby. More people died, and died at a younger age, in the new industrial cities, than in the villages they had come from. Half the children failed to survive beyond the age of five. The increase in the population of cities was because of immigrants, rather than by an increase in the number of children born to families who already lived there.

Deaths were primarily caused by epidemics of disease that sprang from the pollution of water, like cholera and typhoid, or of the air, like tuberculosis. More than 31,000 people died from an outbreak of cholera in 1832. Until late in the nineteenth century, municipal authorities were negligent in attending to these dangerous conditions of life. The medical knowledge to understand and cure these diseases was unknown.
1) When was the survey conducted?
Answer:
In 1842.

2) What was the average lifespan?
Answer:
It was 15 years in Birhingham, 17 in Manchester, and 21 in Derby.

3) What was the cause of the increase in population?
Answer:
The increase in the population of cities was because of immigrants, rather than by an increase in the number of children born to families who already lived there.

4) What are the diseases mentioned here?
Answer:
Cholera, Typhoid, and Tuberculosis.

5) Why were the municipal authorities negligent in attending to these diseases?
Answer:
The medical knowledge to understand and cure these diseases was unknown.

Question 18.
Read the lesson and prepare any four questions relating to it.
Answer:

• How can we say that England was fortunate?
• What was the serious problem in mines?
• Whom was the first locomotive connected to?
• Why did the Krupp family establish the world’s largest arms factory?

Question 19.
What were the relative advantages of canal and railway transportation?
Answer:

• Both were used to transport commodities cheaply.
• Both enhanced the values of the properties.
• The invention and usage took the entire process of industrialisation to a second stage.
• Both reduced the time taken to travel between two places.

Question 20.
Why was Britain the first country to experience modern industrialisation?
Answer:
Reasons:

1. Political stability
2. Modest climate
3. Availability of continuous water power
4. Transportation facilities
5. Abundant wealth
6. Availability of labour
7. Invention of machinery.

Question 21.
Write the favourable conditions which helped the inventions.
Answer:
It is interesting to read about the individuals who brought about these changes during industralisation. Few of them were trained scientists. Education in basic sciences like physics or chemistry was extremely limited until the late nineteenth century, even after the technological inventions described above. Since these inventions did not require a full knowledge of the laws of physics or chemistry on which they were based, advances in science could be and were made by brilliant, intuitive thinkers and persistent experimenters.

They were helped by the fact that England had certain features which other European countries did not. Dozens of scientific journals and published papers of scientific societies appeared in England between 1760 and 1800. There was a widespread thirst for knowledge even in the smaller towns. This was met by the activities of the Society of Arts (founded in 1754), by travelling lecturers, or in ‘coffee houses’ that multiplied through the eighteenth century.

Question 22.
Appreciate the efforts of German to become an Industrialised state.
Answer:

• Germany (erstwhile Prussia) exploited its rich coal fields (Silesia and Rhineland – the Rhur) and iron deposits (Bohemia) to flourish in steel industry.
• With the invention of electric dynamo, they lead electric industry in the world.
• Unification in 1871 made access to iron from Lorraine fields of iron from France.
• Government encouraged industry by providing road/rail transports and markets also.
• It also focused on arnament industry.
• Large banks provided the capital needed.
• By the beginning of 20^th century, Germany had developed a powerful industrial base.

These AP 9th Class Physical Science Important Questions 12th Lesson Units and Graphs will help students prepare well for the exams.

AP State Syllabus 9th Class Physical Science 12th Lesson Important Questions and Answers Units and Graphs

9th Class Physical Science 12th Lesson Units and Graphs Textbook Questions and Answers

Improve Your Learning

9th Class Physical Science 12th Lesson Units and Graphs 1 Mark Questions and Answers

Question 1.
What is Unit?
Answer:
A unit is a standard measure used for comparing measurements.

Question 2.
Why do we use different units for different items?
Answer:
Depending on the quantities of material the units may be expressed.

Question 3.
Write fundamental quantities in MKS system.
Answer:
Mass (m), Length (l) and Time (t).

Question 4.
What are fundamental quantities?
Answer:
Fundamental quantities are those physical quantities that cannot be expressed in terms of other quantities.

Question 5.
What is fundamental unit?
Answer:
Units used to express fundamental quantities are called fundamental units.

Question 6.
Write fundamental units in MKS system.
Answer:
Meter, Kilogram and Second.

Question 7.
What is CGS system?
Centimeter, Grams and Seconds.

Question 8.
What is SI system? When was it introduced?
Answer:
SI system means International System of units. It was introduced in 1971.

Question 9.
List the fundamental quantities that are added to SI system.
Answer:
Electricity, light intensity, quantity of substance, temperature and plane angle.

Question 10.
What is difference between MKS and SI systems?
Answer:

• MKS system has only three fundamental quantities. Those are length, mass and time.
• SI system has eight fundamental quantities. Those are length, mass, time, electricity, light intensity, quantity of substance, temperature, plane angle.

Question 11.
What is derived quantity?
Answer:
The quantities that are obtained by combining fundamental quantities either by multiplication or division or both operations are called derived quantities.

Question 12.
What are derived units?
Answer:
The derived units of measurement derived from the fundamental units.

Question 13.
Write derived units of area and volume.
Derived units of area = m²
Derived units of volume = m³

Question 14.
What are the fundamental units are used to express the units of Force?
Answer:

Hence fundamental units used to express force are kg, m, s.

Question 15.
Which conversion factor is used to convert kilometers into meter?
Answer:
1000.

Question 16.
Which conversion factor is used to convert meters into kilometers?
Answer:
10^-3.

Question 17.
Write conversion factor to convert km/hr into m/s.
Answer:
\(\frac{5}{18}\)

Question 18.
Write some units of measurements expressed in the name of scientists.
Answer:
Newton (N), Pascal (Pa), Joule (J), Watt (W), etc.

Question 19.
What is graph?
Answer:
A pictorial form of representation that shows the relation between two quantities can be called a graph.

Question 20.
What are independent and dependent variables?
Answer:
Independent variables are controlled by us. Whereas dependent variables are changed due to the change in dependent variable.

Question 21.
Which variable is taken on x – axis?
Answer:
Independent variable.

Question 22.
What are grids on graph paper?
Answer:
On a graph paper, there are thick as well as fine vertical and horizontal lines. These intersecting lines form squares or grids.

Question 23.
What is Range?
Answer:
Range = highest value – lowest value.

Question 24.
What is scaling?
Answer:
Pointing of the values in the table on x – axis and y – axis is called scaling.

Question 25.
What is scale?
Answer:
The interval taken pointing values on axis is called scale.

Question 26.
How do you find x – axis scale?
Answer:

Question 27.
What is curved line graph?
Answer:
If a graph is in curved shape, then it is curved line graph.

Question 28.
What is Hooke’s law?
Answer:
The elongation of the spring is proportional to the applied mass within the elastic limit of the spring.

Question 29.
What is slope of the straight line graph?
Answer:

Question 30.
What is slope of a graph?
Answer:
The tan value of the angle at x – axis is the slope of a graph.
tan θ = \(\frac{\Delta \mathrm{y} }{\Delta \mathrm{x}}\)

Question 31.
What is area of a graph?
Answer:
The product of the physical quantity of y – axis and x – axis may explain another physical quantity. Hence, it is said to be area of the graph.

Question 32.
What does slope indicate to the graph of displacement and time?
Answer:
Velocity.

Question 33.
What does area of the graph of acceleration Vs time indicate?
Answer:

Question 34.
Predict shape of the graph if you plot a graph by taking time on x – axis and velocity of a free fall body on y – axis.
Answer:
Straight line.

Question 35.
Guess the shape of the graph if you plot a graph of time and distance covered by a bus.
Answer:
Curved graph.

Question 36.
Rithvik wrote ‘3 kgs of sugar’ on the black board. Correct him by asking a question.
Answer:
Is it correct to mention kg in plural form while writing units?

Question 37.
Karthik got a doubt by seeing ‘3 newtons’ on the black board. What would be it?
Answer:
Which quantity is measured in newtons ?

Question 38.
What are the materials / apparatus required to prove Hooke’s law?
Answer:

1. Spring,
2. Weights,
3. Scale,
4. Stand.

Question 39.
Area, volume, density, mass
a) Write any one fundamental quantity from the above data.
b) Write any one derived quantity from the above data.
Answer:
a) mass.
b) volume.

Question 40.
‘Dheeraj counted distance travelled by him for every 10 min.’
From the above data write independent and dependent variables.
Answer:
Time (min) is independent variable distance is dependent variable.

Question 41.

Plot the data points (6, 4) and (0, 0) in the above graph.
Answer:

Question 42.
How do you remember scientists through units of measurements?
Answer:
Some units are expressed in the names of the scientists like newton, joule, etc. When we use these units, scientists are remember once again.

Question 43.
What is the use of graph?
Answer:

• We can solve so many problems by using graphs.
• We can know the relation between two physical quantities through graphs.

Question 44.
Calculate the Range of 5, 7, 3, 8, 18, 4, 2, 6.
Answer:
Range = highest value – lowest value
= 18-2 = 16.

Question 45.
If the range is 10 and no. of grids horizontally is 20. How can you take scale X-axis?
Answer:

2) I will take 0.5,1,1.5, 2, 2.5,3,3.5, 4, 4.5, 10 on the X-axis. As a scale on x-axis.

Question 46.
How slope of displacement Vs time graph is useful?
Answer:
We can calculate velocity by calculating slope of line in displacement Vs time graph.

Question 47.
How area of velocity Vs time graph is useful?
Answer:
Area of velocity Vs time graph is useful to find the position of the object.

Question 48.

What is the acceleration at ‘B’?
Answer:

Acceleration is 1 m/s².

Question 49.

Find the acceleration at ‘A’.
Answer:

Question 50.

How much distance is travelled by the object from A to B in the graph?
Answer:
Zero.

9th Class Physical Science 12th Lesson Units and Graphs 2 Marks Questions and Answers

Question 1.
What is a unit? Where it be placed?
Answer:

• A unit is a standard measure used for comparing measurements.
• Unit should be placed right side of the magnitude of every physical quantity. For eg : 2 kg, 7 m.

Question 2.
Differentiate fundamental quantities and derived quantities.
Answer:

Fundamental quantity	Derived quantity
1) Fundamental quantities are those physical quantities that cannot be expressed in terms of other quantities.	1) The quantities that are obtained by combining fundamental quantities either by multiplication or division or both are called derived quantities.
2) These are independent.	2) These are dependent.
3) Eg : Mass, length, time.	3) Eg : Area, density, force.

Question 3.
Derive units of density.
Answer:

Question 4.
Write different system of measurements.
Answer:

1. FPS : Foot, Pound, Second.
2. CGS : Centimeter, Gram, Second.
3. MKS : Meter, Kilogram, Second.
4. SI : Meter, Kilogram, Second, Ampere, Candela, Mole, Kelvin, Radian.

Question 5.
Derive units to the given physical quantities.
Answer:

Question 6.
Which of the following are correct? Why?
Answer:
A) m/s
B) m/s/s
C) m-s²
D) 10.kgs
E) Pascal
F) joule
Answer:
A) and F) only are correct
B) two solidus are used – wrong.
C) line break is used – wrong.
D) ‘•’ and plural of kg are used – wrong.
E) capital letter used (P) – wrong.

Question 7.
Write correct form of units in the following.
(j) DB
(ii) mhz
(iii) 20 – m
(iv) kg.m-s^-2
Answer:
(i) dB
(ii) MHz
(iii) 20 m
(iv) Kg.m.s^-2

Question 8.
How do you expect the shape of the given graphs?
(a) a ∝ b
(b) a ∝ \(\frac{1}{\mathbf{b}}\)
Answer:
a) It may be straight line graph.
b) It may be curved line graph.

Question 9.
From the graph,
a) What is indicated by slopes of the lines OA, OB, OC?
b) Which line shows high speed than other lines? Why?

Answer:
a) Slopes of the lines indicate speeds of the objects.
b) OA shows high speed than other lines.
Because it has high slope than others.

Question 10.

a) Which is independent variable?
b) Which is dependent variable?
c) Predict how the graph is.
d) Find the range on Y – axis.
Answer:
a) Mass
b) Weight
c) It may be in straight line.
d) On Y – axis, values are 98, 196, 294, 392, 490.
Range = 490 – 98 = 392

Question 11.
Plot the given data points on the given graph paper and join the dots.
Data points : (8, 10) (20, 15) (40, 22.5) (48, 0)

Answer:

Question 12.
Draw a graph roughly to show uniform velocity of a body.
Answer:

Question 13.
Draw a graph that shows a body without movement after travelling sometime.
Answer:

Question 14.
How do you appreciate the role of graphs in solving problems?
Answer:

• Graphs can be used to compare different physical quantities like time- displacement, time-velocity, pressure-volume, etc. and helps in solve the problems.
• Graphs are very useful to find the path of an object which is in motion and it is easy to calculate velocity, acceleration, position, etc. at particular time and particular point of the object.
• Graphs are very useful minimum, maximum values of some physical quantities. For example to find minimum deviation of a prism graphs are very useful.
• In this way graphs are appreciable for their role in solving problems.

Question 15.
From the given graph find the slope and area at point B.
Answer:

Question 16.
Convert 3 m/s into km/hr.
Answer:

Question 17.
A ball of 100 g mass is thrown with initial velocity of 0.01 km/s. What is its momentum at that time?
Answer:
Momentum = mass × velocity
Here, mass of the ball = 100 gr = 100 × \(\frac{1}{100}\) kg ⇒ m = 0.1 kg
Velocity of the ball = 0.01 km/s = 0.01 × 1000 m/s ⇒ v = 10 m/s
Momentum of the ball = mxv = 0.1 × 10 kg.m/s = 1 kg.m/s

Question 18.

Find the temperature on Day – 4 by using graph.
Answer:

From the graph the temperature on day – 4 is 43°C.

Question 19.
Observe table and answer the following.

i) 12 cm = …………. m
ii) 2 nm = …………. cm
Answer:
i) 12 cm = 12 × 10^-2 m
ii) 2 nm = 2 × 10^-7 cm
[From the table 1 nanometer = 10_-9 m; 1 centimeter = 10^-2 m.
1 nanometer to centimeter conversion factor = 10^-9-(-2) = 10^-7.]

Question 20.
Find the conversion factors
a) Picometers to Meters
b) Gigabytes to Kilobytes.
Answwr:
From the above table,
a) 1 picometer = 10^-12 m; 1 meter = 10° m
Conversion factor to convert picometers to meters = 10^-12-(-0) = 10^-12 m

b) 1 GB = 10⁹ bytes ; 1 KB = 10³ bytes
Conversion factor to convert GB to KB = 10^9-3 = 10⁶ bytes.

Question 21.
Find the conversion factors
a) Megawatts to Kilowatts
b) Kilowatts to Megawatts.
Answer:
From the above table,
a) 1 Megawatt = 10⁶ watts; 1 Kilowatt = 10³ watts
Conversion factor MW to KW = 10^6-3 = 10³ W

b) 1 KW = 10³ W and 1 MW = 10⁶ W
Conversion factor KW to MW = 10^3-6 = 10^-3 W

9th Class Physical Science 12th Lesson Units and Graphs 4 Marks Questions and Answers

Question 1.
Write any four rules of writing units of measurements.
Answer:
1) Values are written as a number followed by a space and a unit symbol.
eg : 24 kg, 2 cm, 5 s.

2) Symbols for derived units formed by multiplication are joined with a dot or a space.
eg : 30 N.m, 30 N.m

3) Symbols are mathematical entities, not abbreviations. So, do not have an appended period / full stop.
eg : 4 kg is correct, but 4 k.g. is incorrect.

4) All symbols for units are written in lowercase.
eg : m, s, kg, etc.

5) Symbols derived from the name of a person use uppercase letter for shortform.
eg : Pa, N, W, etc.

Question 2.
Write steps in the construction of a graph, to the given data in a tabular form.
Answer:

• Take a graph paper. Draw x – axis and y – axis on it.
• Identify independent variable and dependent variable from the data given in the table. Generally independent variables are decided by us, whereas dependent variables are changed due to the change in independent variable. Take independent variable on x – axis and dependent variable on y – axis.
• Calculate range for values taken on x – axis as well as y – axis, by using the formula. Range = highest value – lowest value.
• Determine the scale to be taken on x – axis and y-axis by calculating, range/no. of grids on axis. And mark the scale on the axes.
• Write names of the physical quantity which is taken on the axis. For eg : time (s), distance (m).
• Write the data points from the data given in the table such as (x₁ y₁) (x₂ y₂)
• Label the data points in the graph paper by put a dot where the corresponding horizontal and vertical line intersects of a data point.
• Joint the dots in the graph paper.

Question 3.
Fill the given table with suitable answers.

Answer:
a) N/m²
b) Pa [pascal]
c) s^-1
d) Force
e) m.kg.s^-2
f) m² . kg . s^-2
g) J/s (or) \(\frac{N.m}{s}\)
h) W [watt]

Question 4.
Fill the table with suitable answers.

Derived quantity	Relation with base and derived quantities	Unit
Area	 
Volume
Density
Speed
Velocity
Acceleration
Work
Momentum

Answer:

Derived quantity	Relation with base and derived quantities	Unit
Area	length × breadth	m2
Volume	length × width × height	m3
Density	mass / volume	kg m-3
Speed	distance / time	m s-1
Velocity	displacement / time	m s-1
Acceleration	change in velocity / time	m s-2
Work	force × distance	kg m2 s-2
Momentum	mass × velocity	kg.m.s-1

Question 5.

1) Who took rest while travelling?
2) After 100 min., what is the positions of Padma and Bhavani?
3) Whose speed is uniform?
4) What is the speed of Bhavani?
Answer:

1. Padma
2. Padma at 700 meters and Bhavani at 600 meters from the beginning point.
3. Speed of Bhavani is uniform.
4. \(\frac{600}{100}\)m/min. = 6 m/min.

Question 6.

a) Which physical quantity is taken as independent variable?
b) What is the scale on x – axis?
c) What is the scale on y – axis?
d) How the graph is?
Answer:
a) Distance
b) 1 cm = 100 m
c) 1 cm = 2 min.
d) It is a curved line graph.

Question 7.
Draw a graph to the given data.

Answer:
1) Draw x – axis and y – axis on a graph paper.
2) Here time is independent variable and displacement is dependent variable. So, take time on x – axis and displacement on y – axis.

3) Calculate the ranges of values on x – axis and y – axis.
Range on x – axis = 24 – 4 = 20
Range on y – axis = 15-2 = 13

4) Estimate scale on x – axis and y – axis.

So, scale on x – axis 1 cm = 2 min.
Scale on y – axis 1 cm = 1 km.
Mark the scales on x and y – axis.

5) Write time (min) at x – axis and displacement (km) at y – axis.

6) Write data points or data values as (4, 2) (8, 3) (12, 7) (16, 11) (20, 13) (24, 15).

7) Plot the above data points in the graph paper with dots.

8) Join the data points.

Question 8.
Draw velocity – time graph to the given table.

Answer:
1) Draw x – axis and y – axis on a graph paper.
2) Here time is independent variable and velocity is dependent variable. So, take time on x – axis and velocity on y – axis.

3) Calculate the ranges of values on x – axis and y – axis.
Range on x – axis = 180 – 20 = 160
Range on y – axis = 20 – 5 = 15

4) Estimate scale on x – axis and y – axis.

Take scale as 1 cm = 8 s on x – axis.
1 cm = 1 m/s on y – axis.

5) Write time (s) at x – axis, velocity (m/s) on y – axis.

6) Write data points as (20, 5), (40, 10), (60, 15) (80, 20) (100, 20), (120, 20) (140, 20) (160, 20) (180, 15).

7) Plot the data points in the graph paper with dots.

8) Join the dots.

Question 9.
Show that i) v = u + at, ii) s = ut + ½ at² in graphical method.
Answer:

1) Graph is plotted with time on x – axis and velocity on y – axis.

2) According to the above graph,
Velocity of the object at “t” value ”0″ = u
Velocity of the object at “t” value “t” = v

3) Difference between the time intervals = v – u

4) From the graph, x₁ = 0, x₂ = t, y₁ = u, y₂ = v

5) We know that slope refers acceleration to the velocity – time graph.
Hence acceleration (a) = \(\frac{\mathrm{v}-\mathrm{u}}{\mathrm{t}}\) ⇒ v – u = at ⇒ v = u + at ………… (1)

6) The area between the two straight lines drawn at u, v gives displacement of the object. The area of graph is in the shape of trapezium. It has a rectangle and a triangle.

7) Area of the graph = area of rectangle (ABCD) + area of triangle (DCE)

8) We know that area of the graph of velocity – time gives displacement(s).

Question 10.
Observe the following graph and calculate displacement of the object in 12 sec.

Answer:
1) Displacement (s) = Area of the graph = Area of ABDO rectangle + BDC triangle.
2) Area of the rectangle ABDO = 8 × 20 = 160.
3) Area of the triangle BDC = ½ × 20 × (12 – 8)
= ½ × 20 × 4 = 40.
4) Displacement (s) = 160 + 40 = 200 m.
5) Hence, displacement of the object in 12 sec. = 200 m.

Question 11.
Find the velocity from the graph at A.

Answer:

1. We know that area of the graph of acceleration – time gives velocity (v).
2. Join the line AB.
3. Velocity (v) = Area of ΔABO = ½ × 60 × 120 = 3600 m/s.

Question 12.
Find the force at point ‘B’.

Answer:

We know that
Force= Area of trapezium ABDO.
= Area of triangle AEB + Area of rectangle EODB

Question 13.
Using the following data. Draw displacement time graph.

Using above graph, what is the average velocity in First “4” Seconds
Answer:
Average velocity in first “4” seconds

9th Class Physical Science 12th Lesson Units and Graphs InText Questions and Answers

9th Class Physical Science Textbook Page No. 205

Question 1.
Which is bigger, 2 kg or 100 gr?
Answer:
2 kg.

Question 2.
What would be Rasheeda’s answer?
Answer:
2 kg.

Question 3.
If Rasheeda asked the shop keeper to give 2 sugar, 100 tea powder, can he be able to weigh the items? Why?
Answer:
No, the shop keeper cannot weigh. Because there is no measuring terms (units) to weigh.

Question 4.
Can you name the units of time? What are they?
Answer:
Second, minutes, hours, etc.

Question 5.
Why are they (different units to measure a physical quantity) required?
Answer:
Depending upon the quantity, different units to measure are required.

Question 6.
Can we express the mass of chalk in kilogram?
Answer:
It is difficult to measure directly in kilograms.

9th Class Physical Science Textbook Page No. 206

Question 7.
Why do we use different units for different items?
Answer:
Depending on the quantities of material the units may be expressed.

Question 8.
Why are these called fundamental quantities?
Answer:
These (length, mass, time, etc.) are independent quantities, cannot be expressed in terms of other quantities.

Question 9.
What fundamental quantities are there in the table?
Answer:
Length, mass, time electricity, light intensity, quantity of substance, temperature, plane angle.

Question 10.
What similarities have you noticed in MKS and SI systems?
Answer:
Length, mass, time are common in MKS and SI systems.

Question 11.
How do you find the area of the book?
Answer:
By multiplying length and breadth of the book.

Question 12.
What measurements are required to express area?
Answer:
Length and breadth.

9th Class Physical Science Textbook Page No. 208

Question 13.
How can you convert kilometers into meters?
Answer:
We can convert kilometers into meters by multiplying meters with conversion factor 1000.

9th Class Physical Science Textbook Page No. 211

Question 14.
What is the length of each side (of square grid)?
Answer:
1 cm.

Question 15.
What is the distance between the adjacent thin lines?
Answer:
1 mm.

Question 16.
Which axis is time plotted on and which axis represents distance?
Answer:
Time is plotted on x – axis, y – axis represents distance.

Question 17.
How are these (numbers on x – axis) interpreted?
Answer:
By calculating range of the values of data on x – axis.

Question 18.
What is the difference between the highest and the lowest values?
Answer:
40-5 = 35.

9th Class Physical Science Textbook Page No. 212

Question 19.
What is the advantage of knowing the range of values?
Answer:
If the graph is plotted with the help of calculated values of range, the graph is uniformly distributed through the graph paper and has a correct shape. Otherwise, it will be either too big or too small and will not be any help for analysis.

Question 20.
How to identify values on x-axis and y-axis?
Answer:
By determine the scale.

Question 21.
How to determine scale?
Answer:

Question 22.
Which values of distance in the table are equal to the values marked on y-axis?
Answer:
3, 12, 24, 24, 30, 33.

9th Class Physical Science Textbook Page No. 213

Question 23.
What is the shape of the line in the graph?
Answer:
It is curved line.

Question 24.
Did you notice any elongation of the spring?
Answer:
Yes, I noticed elongation of the spring.

Question 25.
How much was the elongation?
Answer:
Some extend. It can be calculated by difference in the lengths of the spring.

9th Class Physical Science Textbook Page No. 214

Question 26.
Can you identify the independent and the dependent variables?
Answer:
Mass is independent variable and elongation of the spring is dependent variable.

9th Class Physical Science Textbook Page No. 215

Question 27.
At what point plunger cannot move forward.
Answer:
It is depending upon conditions of the experiment.

Question 28.
Do you experience any pressure with air?
Answer:
Yes.

9th Class Physical Science Textbook Page No. 217

Question 29.
Let us say what is the slope of x – axis?
Answer:
Slope of the x – axis is zero.

9th Class Physical Science Textbook Page No. 218

Question 30.
What does the ratio explains the physical quantities on the y – axis and x – axis?
Answer:

The ratio explains the physical quantities on the y – axis and x – axis is velocity.

Question 31.
What is the velocity of the object at 1.5 seconds of time?
Answer:

9th Class Physical Science Textbook Page No. 207

Question 32.
Is litre a fundamental unit or a derived unit?
Answer:
One litre is the volume of a cube with 10 cm sides. (10 cm × 10 cm × 10 cm)
(or) 1 L = 10^-3 m³
Hence, litre is a derived unit.

9th Class Physical Science 12th Lesson Units and Graphs Activities

Activity – 1

Question 1.
You have noticed that different units are used to measure different materials. Based on your past experience fill in the table with suitable units of measurements used in general, put a tick mark.

Activity – 2 Derived Quantities – Derived Units

Question 2.
1) Let us measure the surface area of your book using a scale.
2) Measure the length and breadth of the book.
3) Area of the book can be obtained by multiplying length and breadth.
4) Length = ……………………..
5) Breadth = ……………………
Is area of fundamental quantity?
Answer:
No.

Which fundamental quantity is used to derive area?
Answer:
Length.

From the activity, we can say area is a derived quantity, which is obtained by multiplication of length and breadth which are fundamental quantities.

Activity 3

Question 3.
Let us observe the given table and try to find out fundamental and derived units for the given information.

1) Which derived units are obtained by the multiplication of fundamental units?
Answer:
Area, volume

2) Which units are derived from only the fundamental quantity length?
Answer:
Area, volume

3) Which derived quantity has no units?
Answer:
Relative density

4) What are the fundamental units of volume?
Answer:
Length

5) What quantities are derived from time?
Answer:

1. Velocity
2. Acceleration
3. Force
4. Pressure

Activity – 4

Question 4.
Draw a curved line graph to the given table.
Answer:
1) Anitha travels to her grandmother’s village by car.
2) She observed the Odometer (the instrument that measures the distance travelled) fitted in the car.
3) She recorded the reading shown by the odometer once every 5 minutes for 40 minutes.
4) Look at the table prepared by Anitha.

5) ‘We show the relation between two quantities using a graph.
6) Here time is independent variable and distance is dependent variable.
7) The steps in the construction of a graph

i) Draw x – axis and y – axis on a graph paper.
Plot time on x – axis as it is independent variable whereas distance on y – axis as it is dependent variable.

ii) Find the range on x – axis
Range on x – axis = highest value – lowest value = 40 – 5 = 35 Find the range on y – axis
Range on y – axis = highest value – lowest value = 33 – 3 = 30

iii) Determine the scale

iv) Names on the axis
Write time (min.) on x – axis.
Write distance (km) on y – axis.

v) Write the data points from the table.
(0, 0), (5, 3), (10, 8), (15, 12), (20, 19), (25, 24), (30, 24), (35, 30), (40, 33).

vi) Labelling of data points :
Label above data points with dots where vertical and horizontal lines are intersect to the respective data points.

vii) Join the dots.

What is the shape of the line graph?
Answer:
It is curved in shape.

Activity 5

Question 5.
Draw a straight line graph to the given table.

Answer:

• Take a spring / rubber band.
• Measure the length of the spring with a scale.
• Fix the spring to the stand.
• Suspend the weight to the second end of the spring.
• Now, again measure the length of the spring.
• Calculate the elongation.
•  This way, keep on changing the weights and measure the elongation of the spring with scale.

Record the readings in the table.

9) Here mass (gm) is independent variable and elongation is dependent variable.
10) Plot the graph.

1. Which quantity is taken on the x-axis ? In what units it was expressed? Why was it taken on the x-axis?
Answer:

1. Mass is taken on the x – axis.
2. It was expressed in grams.
3. Mass is independent variable, so it was taken on the x – axis.

2. Which quantity is taken on the y-axis? In what units it was expressed? Can this be called an independent variable?
Answer:

1. Elongation of the spring was taken on the y – axis.
2. It was expressed in millimeters.
3. It cannot be called as independent variable, because the values of elongation are obtained in the experiment.

3. The value of range on the x – axis
Answer:
Range = 50 – 0 = 50

4. The value of range on the y-axis
Answer:
Rang = 10 – 0 = 10

5. Scale on the x-axis
Answer:
10

6. Scale on the y-axis
Answer:
2

7. Data values on the x-axis
Answer:
0, 10, 20, 30, 40, 50.

8. Data values on the y-axis
Answer:
0, 2, 4, 6, 8, 10.

9. What is the shape of the line that joined the intersecting points?
Answer:
Straight line.

10. What does the slope of a curve tell us?
Answer:
Relation between mass and extension of the spring.

11. What is the reason for the elongation of the spring?
Answer:
Due to mass suspension to the spring.

12. What relation did you notice between the mass and elongation of spring?
Answer:
Elongation is directly proportional to mass.

13. Wliat could be the relation between the two quantities when the graph is a straight line?
Answer:
It could be directly proportional.

14. Based on the graph, which of the following sentences are correct?
a) If mass increases the elongation of spring increases.
b) If mass decreases the elongation of spring increases.
c) Even if mass increases, there will be no change in the elongation of the spring.
Answer:
a), b) are correct.

Activity – 6

Question 6.
Plot a graph showing inversely proportional measurements.
Answer:

1. Take a 50 ml syringe.
2. Fill the syringe with air by pulling a plunger.
3. To avoid escape of air from syringe close the nozzle of syringe with your finger.
4. Now push (apply the force) the plunger slowly.
5. While you are pushing the plunger you may experience more pressure with the decrease of volume of air in syringe, hence you need to apply more force on plunger.
6. Let us find out the relation between the pressure and volume of air.
7. Observe the following data table.

Physical Quantity on x – axis
Answer:
Pressure

Physical Quantity on y – axis
Answer:
Volume

What is the independent variable?
Answer:
Pressure

What is the dependent variable?
Answer:
Volume

What is the range of values on vertical axis?
Answer:
Range = 50 – 18.7 = 31.3

What is range of values on horizontal axis?
Answer:
Range = 3.2 – 1.2 = 2

What is the shape of the graph?
Answer:
Curved in shape (Parabolic).

What relation you noticed between two physical quantities based on data points in the graph?
Answer:
I have noticed that there is decrease in volume with increase of pressure. Hence these two quantities said to be inversely proportional.

Activity – 7

Question 7.
Observe the following graphs and write your analysis in the given table.

These AP 9th Class Social Studies Important Questions 8th Lesson Service Activities in India will help students prepare well for the exams.

AP State Syllabus 9th Class Social 8th Lesson Important Questions and Answers Service Activities in India

9th Class Social 8th Lesson Service Activities in India 4 Marks Important Questions and Answers

Question 1.
‘Service sector is beyond the other two sectors in providing employment’.
“Ramesh is a self employee who established an internet centre after completion of B.Tech. He also provided employment for two more persons”.
‘Service sector plays key role in providing employment’ comment on it. (SA-III : 2015-16)
Answer:
Yes. Services sector plays key role in providing employment by the following ways.

1. There has been tremendous change in the communication technology which has opened a wide range of jobs for educated people.
2. Business Process Outsourcing (BPO) has brought in new kinds of employment opportunities.
3. They provide services to people located across the globe using telecommunication links.
4. The entertainment industry creates jobs to work in various print media firms, cable television channels.
5. We see number of internet cafes and telephone booths in most of the cities and towns.
6. The advertising industry has also brought new job opportunities.
7. Many new jobs are available in Banking and insurance sectors.

Hence service sector can reduce educated unemployment in our country.

Question 2.
The table below shows the number of workers (in lakhs) employed in different service activities in large government enterprises in 1991 and 2010. Study the table and answer the question given below. (SA-II : 2018-19)

Service sector activities	Government jobs
	1991	2010
Wholesale and retail trade	1.5	1.7
Transport, storage and Communications	30.3	25.3
Finance, insurance, real estate etc.	11.9	14.1
Community, social and personal services	92.3	90.5

a) Which service activity provided least employment?
b) Write any two jobs related to community, social and personal services.
c) What kind of service activity jobs have shown maximum decrease in 2010?
d) What kind of service activity jobs has government-generated most in 2010?
Answer:
a) Wholesale and retail trade

b)

1. Washing and drycleaning work
2. Beauty treatment
3. Tailoring work
4. Barbour work (Hair cutting)
5. Who runs the photo studio.

c) Transport, storage and communications.

d) Finance, insurance, real estate etc.

9th Class Social 8th Lesson Service Activities in India Important Questions and Answers

Question 1.
How is service sector different from other sectors?
Answer:

• Other sectors, agriculture and industry produce goods that are tangible.
• But service activities do not produce any tangible good.
• But service activities fulfill the needs cater the requirements of people or organisations.
• They are also essential for agriculture and industrial activities.
• Non-production of commodity or good is the essential nature of service sector.

Question 2.
Is service sector, the heaven of dream jobs?
Answer:

• No, I don’t think so.
• Dream jobs in service sector are at a rate of one in tens of thousands of jobs.
• Remaining, especially uneducated and less educated do jobs with meagre wages.
• Those who have dreams are also under constant pressure and job stress.

Question 3.
Read the following case history and answer the following questions.

My lifestyle has improved due to IT. In college, I had just two trousers and two shirts. Now, I have many shirts. I buy good quality clothes and I don’t have to think about how much I spend. So definitely, working in the software industry has added comfort to my life. Earlier, there were a lot of financial problems in the family – my brothers and sisters were not able to study properly due to this, and I am very happy that I have been able to solve this problem. But it is a stressful and mechanical life; there is no social life. In my hometown, people were always there around me – neighbours and relatives. There was always someone to go and talk to but here, it’s difficult to make friends.

1) What was the position of the family before getting a job?
Answer:
Earlier there were a lot of financial problems in the family – his brothers and sisters were not able to study properly due to this.

2) What is his family’s financial position now?
Answer:
Working in software has added comfort to his life, and his brothers and sisters are able to study properly now.

3) Is the individual happy with his lifestyle?
Answer:

• He is earning good salary and that added comfort to his life.
• But at the same time the job is very stressful and his life is mechanical.
• He is missing his village, neighbours and relatives.

Question 4.
What is the work going on here in the given picture? Describe it in five sentences.
Answer:

1. It is a call centre job.
2. A call centre is an office where people work answering or making telephone calls for a particular company or customer regarding certain information.
3. The information may be regarding customer’s bank deposits or about their hospital records.
4. There will be three shifts and employees may have to work during nights too.
5. Salaries are high and at the same time lots and lots of stress in the job can be experienced.

Question 5.
What services, in your opinion, are desired today?
Answer:

• India faces an acute shortage of skilled human resources in the health sector. So health services are desired today.
• More infrastructure service is the need of the hour. So roads, hospitals and educational institutions are to be set up.
• We need good storage facilities as well as credit facilities.
• New economic policies in India shall emphasize the expansion of service activities.

Question 6.
Why do you think more people are engaged in low income service activities today?
Answer:

• With lack of job opportunities many people today are employed in low income services.
• Closure of factories forced workers to work as small vendors, rickshaw pullers and other low income service professions.
• People from rural areas are not getting opportunities in urban areas.
• They shift to many unskilled low earning employment opportunities in services.

Question 7.
Many unskilled have low earning employment opportunities in service sector. State your opinion.
Answer:

• People from rural areas come to work in the city but there are not enough employment opportunities in urban areas.
• Hence most of the unskilled are earning their livelihood as small vendors, rickshaw pullers, etc.
• They are unable to make both ends meet.

Question 8.
New job opportunities are depressing the employees. Comment on it (especially in IT).
Answer:

• New jobs are providing good salaries but the employees are also expected to work very long hours.
• The life is very stressful and mechanical.
• There is no social life.
• These jobs definitely depress the employees.

Question 9.
What measures are taken by companies to reduce cost and avoid paying benefits to workers?
Answer:

• In order to reduce cost and avoid paying health, pension and provident fund benefits to workers, industries ‘outsource’ security services to security agencies.
• Many companies outsource their work for research and development, accounting, legal services, customer service, public relations etc.

Question 10.
Many people work in service jobs. Few people do voluntary service. What measures would you take to distinct them?
Answer:

• Voluntary service means that is done free of cost or out of love and devotion.
• It doesn’t contribute to their livelihood.
• They have other occupation but do this as charity.
• On the otherhand, the people who work in service sector earn livelihood through it.
• They do specialised services required for people or organisations.