AP 10th Class Physical Science Model Paper Set 10 with Solutions

Solving AP 10th Class Physical Science Model Papers Set 10 regularly is an effective strategy for time management during exams.

AP SSC Physical Science Model Paper Set 10 with Solutions

Time: 2 Hours
Max. Marks: 50

Instructions:

• The question paper consists of 4 sections and 17 questions.
• Internal choice is available only for Q.No.12 in section III and for all the questions in section IV.
• In 2 hours, 15 minutes is allotted to read the question paper.
• All answers shall be written in the answer booklet only.
• Answers shall be written neatly and legibly.

Section – I (8 × 1 = 8 Marks)

Note:
1) Answer all the questions.
2) Each question carries 1 marks.

Question 1.
Guess, why should a magnesium ribbon is cleaned before burning in air?
Answer:

1. Magnesium is a highly reactive metai.
2. It reacts with oxygen to form a thin layer of oxide on its surface.
3. This oxide layer prevents further corrosion of the metal
4. Therefore, magnesium is cleaned with sandpaper before burning to remove this layer and ensure proper reaction with moisture or air.

Question 2.
Bases which are solulde in water are called
Answer:
Alkalis

Question 3.

Substance	Bleaching Powder	Washing Soda
Formula	CaOCl2	NaCO3

Which of the above substance is used to make drinking water free from germs?
Answer:
Bleaching Powder (CaOCl₂)

Question 4.
Give two examples of amphoteric oxides.
Answer:
Al₂O₃, ZnO

Question 5.
What is the industrial application of hydrogenation?
Answer:
It is used to prepare vegetable ghee from vegetable oils.

Question 6.
Which one of the following materials cannot be used to make a lens?
a) Water
b) Glass
c) Plastic
d) Clay
Answer:
d) Clay

Question 7.
Draw the symbol of electric resistance.
Answer:

Question 8.
How is a voltmeter connected in the circuit to measure the potential difference between two points?
Answer:
A voltmeter is connected in parallel to a circuit, with its positive terminal attached to the point of higher potential and its negative terminal connected to the point of lower potential.

Section – II (3 × 2 = 6M)

Note:
1) Answer all the questions.
2) Each question carries 2 marks.

Question 9.
The general formula of alkanes is C_nH_2n+2 Then write the first two alkanes.
Answer:
The first two alkanes-are CH₄, and C₂H₆.

Question 10.
What can you predict about the mirror, if its magnification is +1 ? Write any one characteristic of the image formed.
Answer:
Magnification, m = +1
Here,’+’ Indicates a virtual image.
T Indicates that the object size and image size are the same.

Question 11.
An electric refrigerator rated 400 W operates 8 hours/day. What is the cost of the energy for 30 days at 3 per kWh?
Answer:
The total energy consumed by the refrigerator in 30 days would be 400 W × 8.0 hours / day × 30 days = 96000 Wh = 96kW h
Thus the cost of energy to operate the refrigerator for 30 days is 96 kW h × Rs. 3,00 per kW h = Rs. 288.00.

Section – III (3 × 4 = 12M)

Note:
1) Answer all the questions.
2) Each question carries 4 marks.

Question 12.
Draw any one of the following diagrams:
A) Draw the ray diagrams of image formed when the object is placed in front of a biconvex lens in the following positions,
a) at infinity.
b) at F₁.

(OR)
B) Draw the diagram which shows that acid solution in water conducts electricity.
Answer:

Question 13.
How can you appreciate the role of pH of acids and bases in our everyday life?
Answer:
1) Survival of Aquatic Life:
a) The pH level of water plays a vital role in the survival of aquatic organisms.
b) When acid rain, having a pH lower than 5.6, enters rivers or lakes, it decreases the pH of the water.
c) Such a drop in pH can make the environment unsuitable for many aquatic species, affecting their survival.

2) Plant Growth:
a) Plants need a specific pH range in the soil for proper and healthy growth.
b) The pH level of the soil greatly influences plant health and nutrient absorption.
c) Therefore, knowing the soil’s pH helps in determining which plants can grow best in a particular area.

3) Digestive System:
a) The pit within thefliuman digestive system is crucial for proper digestives.
b) The stomach produces hydrochloric acid to aid in digestion without harming itself. Imbalances in stomach pit can lead to indigestion, which is alleviated by using bases called antacids to neutralize excess stomach acid

4) Tooth Decay Prevention :
a) Tooth decay is influenced by the pet in the mouth.
b) When the pH drops below 5.5, tooth enamel can corrude, leading to decay.
c) Bacteria in the mouth produce acida from food particles, causing this drop in pH
d) Maintaining oral hygiene and using basic toothpaste can neutralize excess acid. preventing tooth decay.

5) Chemical Warfare in Nature :
a) Some animals and plants use chemicals with varying pH values for self-defence
b) For example, bee stings infect an acidic substance, causing pain and irritation, which can be relieved with a mild base.
c) Stinging nettle leaves inject methanoic acid, causing burning pain, which can be neutralized with a base like baking soda. Because of the above importance’ of pH of acids and bases. I appreciate the role very much.

Question 14.
It is given that the focal length (f) of a convex lens is half of its radius of curvature (R) Then complete the following table.

f(cm)	R(cm)
	32
12
	45
26

Answer:

f(cm)	R(cm)
16	32
12	24
22.5	45
26	52

Section – IV (3 × 8 = 24 M)

Note:
1) Answer all the questions.
2) Each question carries 8 marks.
3) Each question has an internal choice.

Question 15.
A) What is myopia? How can it be corrected, explain with neat diagrams?
Answer:
Myopia or short sightedness : Myopia is a defect of vision in which a person can see nearby objects clearly but cannot see distant objects distinctly beyond a certain distance. This defect is commonly found among children.

Cause of Myopia:
i) The eyeball becomes elongated along its axis, increasing the distance between the eye lens and the retina.
ii) The focal length of the eye lens decreases due to excessive curvature of the cornea.

As a result of these factors, the parallel rays from distant objects converge at a point in front of the retina instead of directly on it, making distant objects appear blurred (as shown in Fig. b). To see the object clearly, it must be brought closer to the eye at a specific point F, where the image is focused on the retina (as shown in Fig. a). Hence, the far point of a myopic eye is not at infinity but only a few metres away.

B) Explain:
i) Why is the tungsten used almost exclusively for filament of electric lamps?
ii) Why is the series arrangement not used for domestic circuits?
Answer:
i) Tungsten is primarily used as the filament in electric lamps because of its very high melting point (around 3300°C). This property allows it to withstand high temperatures without melting, making it ideal for use in incandescent bulbs.

ii) Series connections are not preferred in domestic wiring because if one appliance or component fails, the entire circuit gets interrupted, causing all connected devices to stop working. This makes the arrangement inconvenient arid inefficient for household use.

Question 16.
A) Balance the following chemical equations.
a) HNO₃ + Ca(OH)₂, → Ca(NO₃)₂ + H₂O
b) NaOH + H₂SO₄ → NaSO₄+ H₂O
c) NaCl + AgNO₃ → AgCl + NaNO₃
d) BaCl₂ + H₂SO₄ → BaSO₄ + HCl
Answer:
a) 2HNO_3(aq) + Ca(OH)_2(aq) → Ca₂(NO₃)_2(aq) + 2H₂O(_l).
b) 2NaOH_(aq) + H₂SO_4(aq) → Na₂SO_4(aq) + 2H₂O(_l)
c) NaCl_(aq) +AgNO_3(aq) → AgCl_(s) + NaNO_3(aq)
d) BaCl_2(aq) + H₂ SO_4(aq) → BaSO_4(s) + 2HCl_(aq)

B) Explain the mechanism of the cleaning action of soaps.
Answer:

1. Most dirt contains oily substances, and since oil does not dissolve in water, it cannot be removed by water alone.
2. Soap molecules are sodium or potassium salts of long- chain carboxylic acids.
3. Each soap molecule has two distinct ends a hydrophilic end that is attracted to water and a hydrophobic end that is attracted to oil or grease.
4. When soap is added to water, its molecules arrange themselves into structures called micelles, where the hydrophobic ends attach to the oil droplets while the hydrophilic ends face outward toward the water.
5. This process leads to the formation of an emulsion in water, trapping the oily dirt within the micelles.
6. The soap micelles help lift the dirt and grease from the surface, allowing it to be washed away easily, leaving clothes or surfaces clean.

Question 17.
A) Explain an activity to observe magnetic field lines near a bar magnet.
Answer:
Aim: To plot of a complete pattern of the field lines of bar magnet with the help of a com¬pass needle.

Apparatus required: A sheet of white paper, a drawing board, adhesive tape, a bar mag¬net, a compass needle and a pencil.

Procedure:

1. Take a small compass and a bar magnet.
2. Place the magnet on a sheet of white paper fixed on a drawing board, using some adhesive material.
3. Mark the boundary of the magnet.
4. Place the compass near the north pole of the magnet. How does it behave? The south pole of the needle points towards the north pole of the magnet. The north pole of the compass is directed away from the north pole of the magnet.
5. Mark the position of two ends of the needle.
6. Now move the needle to a new position such that its south pole occupies the position previously occupied by its north pole.
7. In this way, proceed step by step till you reach the south pole of the magnet as shown in fig. (a).
   
8. Join the points marked on the paper by a smooth curve. This curve represents a field line.
9. Repeat the above procedure and draw as many lines as you can. You will get a pattern shown in fig. (b). These lines represent the magnetic field around the magnet. These are known as magnetic field lines.
10. Observe the deflection in the compass needle as you move it along a field line. The deflection increases as the needle is moved towards the poles.

Observations:
1) The deflection of the compass needle increases as it is moved towards the poles.
2) This is because the magnetic field is stronger near the two poles and hence exerts larger force on the compass needle in such regions.

Conclusion:

1. Magnetic Beld is a quantity that has both direction and magnitude.
2. The direction of the magnetic held is taken to be the direction in which a north pole of the compass needle moves inside it
3. Therefore it is taken by convention that the field lines emerge from north pole and merge at the South pole (vote the arrows marked on the fieid lines in fig.)
4. Inside the magnet the direction of fieid lines is from its south pole to its north pole Thus the magnetic field lines are closed curves.

(OR)
B) Write an activity to understand the rusting of iron nails in the presence of air and moisture.
Answer:
Aim: To demonstrate that both air and water are essential for rusting to occur.
Materials Required: Three boiling tubes, clean iron nails, corks, anhydrous calcium chloride, and oil.

Procedure:

1. Take three clean test tubes and place iron nails in each.
2. Label them as A, B, and C. Pour some- water into test tube A and seal it with a cork.
3. In test tube B, add boiled distilled water and pour about 1 ml of oil on top. The oil layer prevents air from dissolving in the water. Cork the tube tightly.
4. In test tube C, place some anhydrous calcium chloride and cork it. The calcium chloride absorbs any moisture present in the air.
5. Leave all three test tubes undisturbed for a few days and then observe.

Observation :
The iron nail in test tube A gets rusted because both air and water are present. In test tube B, the nail does not rust as there is water but no air. In test tube C, rusting does not occur because there is neither air nor water.

Conclusion: Rusting of iron takes place only in the presence of both air and water.