Class 7 Science Chapter 3 MCQ Heat
MCQ on Heat Class 7
I. Multiple Choice Questions (1 Mark)
Select and write the most appropriate option out of the four options given
Question 1.
The degree of hotness or coldness of a body is measured by
A) thermometer
B) ammeter
C) barometer
D) odometer
Answer:
A) thermometer
Question 2.
A reliable measure of the hotness of an object is called its
A) pressure
B) speed
C) density
D) temperature.
Answer:
D) temperature.
Question 3.
The normal body temperature measured using a clinical thermometer on the Celsius scale is
A) 37°C
B) 45°C
C) 57°C
D) 67°C
Answer:
A) 37°C
Question 4.
The range of temperature on a clinical thermometer is
A) 37°C to 45°C
B) 32°C to 45°C
C) 35°C to 42°C
D) None of these
Answer:
C) 35°C to 42°C
Question 5.
The range of a laboratory thermometer is
A) 10°C to 110°C
B) -110°C to -10°C
C) -110°C to 10°C
D) -10°C to 110°C
Answer:
D) -10°C to 110°C
Question 6.
Mercury is not used in
A) clinical thermometers
B) laboratory thermometers
C) digital thermometers
D) all of these
Answer:
C) digital thermometers
Question 7.
A ………… prevents the mercury level from falling on its own.
A) kink
B) bulb
C) thread
D) glass tube
Answer:
A) kink
Question 8.
Convection of heat takes place in
A) solids only
B) gases only
C) liquids only
D) conduction of heat.
Answer:
D) conduction of heat.
Question 9.
Identify the odd one out.
A) Wooden ruler, rubber gloves
B) Silver chain, plastic wrap
C) Needle, ceramic bowl
D) Sand paper, stainless steel spoon
Answer:
A) Wooden ruler, rubber gloves
Question 10.
The handles of cooking vessels are covered with plastic or wood because
A) it is customary
B) they are attractive
C) they are good conductors of heat
D) they are bad conductors of heat.
Answer:
D) they are bad conductors of heat.
Question 11.
By which process does the Sun’s heat reach the Earth ?
A) Convection
B) Transpiration
C) Radiation
D) Conduction
Answer:
C) Radiation
Question 12.
The phenomenon involved in the formation of sea breeze and land breeze is [ ]
A) conduction
B) convection
C) radiation
D) none of these
Answer:
B) convection
Question 13.
The woollen clothes keep us warm during winter because
i) wool is a conductor
ii) wool is an insulator
iii) wool traps air
iv) wool absorbs heat quickly.
A) (i) and (ii)
B) (ii) and (iii)
C) (i) and (iii)
D) (iii) and (iv)
Answer:
B) (ii) and (iii)
Question 14.
A polished, silvery surface is a
A) poor absorber and good radiator of heat
B) good absorber and good reflector of heat
C) good absorber and bad radiator of heat
D) poor absorber and good reflector of heat.
Answer:
D) poor absorber and good reflector of heat.
Question 15.
Petrol storage tanks are not painted black because
A) black is a good absorber of radiation
B) black is bad conductor of heat
C) black is good conductor of heat
D) black is bad emitter of radiation.
Answer:
A) black is a good absorber of radiation
Question 16.
Which of the following conditions lead to the blowing of sea breeze in coastal areas?
i) Day time
ii) Night time
iii) Hot land and cold sea
iv) Cold land and warm sea
A) (i) and (iv)
B) (ii) and (iii)
C) (ii) and (iv)
D) (i) and (iii)
Answer:
D) (i) and (iii)
Question 17.
……….. is Aluminium is a better conductor of heat than wood. It is so because
A) aluminium has a higher specific heat capacity than wood
B) aluminium has a higher mass than wood
C) aluminium has a higher density than wood
D) aluminium has more free electrons than wood.
Answer:
D) aluminium has more free electrons than wood.
Question 18.
Birds glide effortlessly in the air with the help of
A) convection currents of air.
B) conduction of heat in the air.
C) radiation of light through the atmosphere.
D) none of these
Answer:
A) convection currents of air.
Question 19.
Which of the following statements are true ?
i) Pipes are painted black to minimise transfer of thermal energy.
i) Aluminium foils are used to keep food warm.
iii) We wear white clothes to keep ourselves cool during summer.
iv) We wear white clothes to keep ourselves warm during winter.
A) (i), (ii) and (iii)
B) (ii), (iii) and (iv)
C) (i), (ii) and (iv)
D) (i), (iii) and (iv)
Answer:
A) (i), (ii) and (iii)
Question 20.
When a solid mels, the temperature remains same even though heat is being supplied because
A) the molecules are moving faster
B) the molecules are far apart
C) the solid is not absorbing any heat
D) the heat is being used to break up the intermolecular bonds.
Answer:
D) the heat is being used to break up the intermolecular bonds.
Question 21.
Aadvik has difficulty in opening the metal lid of a glass jar of peanut butter. His mother asked him to place the lid of the jar in hot water. The reason was that the hot water will cause the
A) glass jar to expand more than the metal lid expands
B) metal lid to expand more than the glass jar expands
C) metal lid to contract and the glass jar to expand
D) metal lid to expand and the glass jar to contract.
Answer:
B) metal lid to expand more than the glass jar expands
II. Fill in the blanks
1. The device used for measuring the temperature of a human body is …………
Answer: Clinical thermometer
2. For the correct measurement on a clinical thermometer, the mercury level should be below …………
Answer: 35°C
3. The range of a clinical thermometer in °F is …………
Answer: 94°F to 108°F
4. …………is a metal used In thermometer.
Answer: Mercury
5. In vacuum, transfer of heat takes place by the process of…………
Answer: radiation
6. Water and air are ………… conductors of heat.
Answer: poor
7. The handles of cooking utensils are made of …………
Answer: insulator
8. Transfer of heat takes place In solids by the process of …………
Answer: conduction
9. Solids ………… on heating and contract on …………
Answer: expand, cooling
10. The water in the black container becomes ………… than that in white container after exposing to the Sun.
Answer: warmer
11. Black colour is a ………… absorber of heat.
Answer: good
12. We prefer ………… coloured clothes in summer and ………… coloured clothes in winter.
Answer: light, dark
13. Sweating causes cooling by …………
Answer: evaporation
14. The difference between lower fixed point and upper fixed point is divided into ………… parts on a Celsius scale.
Answer: hundred
15. The minimum possible temperature is ………… K.
Answer: 0
16. The upper fixed point of thermometer is taken to be the ………… point of water.
Answer: boiling
17. The freezing point of water on the Fahrenheit scale is …………
Answer: 32°F
18. Density of a liquid ………… on heating.
Answer: decreases
19. SI unit of temperature is …………
Answer: Kelvin
20. One calorie is nearly equal to ………… joule.
Answer: 4184
III. True Or False
Identify the following statements are True or False.
1. Touching is a reliable measure of the hotness of an object.
Answer: False
2. Temperature of any object cannot be determined.
Answer: False
3. Thermometer is used to measure the temperature of any object.
Answer: True
4. Temperature of hot milk can be measured by clinical thermometer.
Answer: False
5. The temperature of human body could be slightly higher or slightly lower than 37°C
Answer: True
6. A temperature of 32°C can be measured on a clinical thermometer.
Answer: False
7. Thermometer should be washed before and after use.
Answer: True
8. House are made of building materials like bricks, mud and grass as these are good conductors of heat.
Answer: False
9. Aluminium is an insulator of heat.
Answer: False
10. Conduction and convection do not require any medium but radiation requires a medium for heat to flow.
Answer: False
11. Heat increases the temperature of a body.
Answer: True
12. All hot objects emit radiant energy.
Answer: True
13. A good conductor of heat is not necessarily a good conductor of electricity. [ ]
Answer: True
14. 0°C is equivalent to 273 K
Answer: True
15. Freezing point of alcohol is much lower than that of mercury.
Answer: True
16. Monsoon occurs due to convection current.
Answer: True
17. Liquids expand more than solids on heating.
Answer: True
18. 310 K is the normal temperature of human body.
Answer: True
19. As the water kept at room temperature heats up, its volume decreases.
Answer: False
20. – 40°C and – 40°F are identical temperatures.
Answer: True
21. The convection currents produced due to warm sea and cold land are called land breeze.
Answer: True