1. In a refrigerator, the cooling system should always be placed at the:
a) Top
b) Bottom
c) Middle
d) Any position
Answer: a
2. Which device detects radiant heat most effectively?
a) Liquid thermometer
b) Six’s maximum and minimum thermometer
c) Constant volume air thermometer
d) Thermopile
Answer: d
3. Why do two thin shirts keep you warmer than one thick shirt in winter?
a) Two shirts act like a thick one, blocking heat loss
b) The fabric layers act as conductors
c) The air trapped between the shirts acts as an insulator
d) Radiation is prevented entirely
Answer: c
4. Why is water used in hot water bags?
a) Easily available
b) Cheap and non-toxic
c) High specific heat capacity
d) Heats up quickly
Answer: c
5. A black body can absorb radiation of:
a) Only short wavelengths
b) Only medium wavelengths
c) Only long wavelengths
d) All wavelengths
Answer: d
6. Why are gas thermometers more sensitive than liquid thermometers?
a) Gases have a higher expansion coefficient
b) Gases are lighter
c) Gases have lower specific heat
d) Gases have higher specific heat
Answer: a
7. Boiling point of a liquid varies with:
a) Pressure
b) Temperature
c) Volume
d) Density
Answer: a
8. Mud houses stay cooler in summer and warmer in winter compared to brick houses because:
a) Mud is a good conductor
b) Mud is a poor conductor
c) Mud acts as an insulator
d) Evaporation cools in summer, and sun warms in winter through gaps
Answer: b
9. SI unit of temperature is:
a) Kelvin
b) Joule
c) Celsius
d) Fahrenheit
Answer: a
10. A real gas can be liquefied by pressure only when its temperature is at or below the:
a) Room temperature
b) Inversion temperature
c) Boyle temperature
d) Critical temperature
Answer: d
11. Relative humidity is expressed in:
a) Grams
b) Kilograms
c) Percent (%)
d) Ratio
Answer: c
12. What determines the color of a star?
a) Temperature
b) Distance
c) Radius
d) Atmospheric pressure
Answer: a
13. The freezing point of fresh water is:
a) 3°C
b) 5°C
c) 0°C
d) 4°C
Answer: c
14. A temperature change of 10°C corresponds to how much on the Fahrenheit scale?
a) 18°F
b) 21°F
c) 10°F
d) 15°F
Answer: a
15. Why does water from a hand pump feel warm in winter?
a) Our body temperature is low in winter
b) The Earth’s subsurface is warmer than the air
c) Pumping action produces heat
d) Water absorbs ambient heat
Answer: b
16. What is temperature inversion?
a) Positive lapse rate
b) Negative lapse rate
c) Neutral lapse rate
d) None of these
Answer: b
17. Ocean currents are a result of which heat transfer method?
a) Convection
b) Conduction
c) Insulation
d) Radiation
Answer: a
18. Who invented the Celsius (Centigrade) scale?
a) Anders Celsius
b) Daniel Gabriel Fahrenheit
c) William Thomson
d) Wright Brothers
Answer: a
19. How much mechanical energy is needed to melt 1 gram of ice at 0°C?
a) 4.2 cal
b) 80 cal
c) 336 cal
d) 2268 cal
Answer: b
20. Gas thermometers are more sensitive than liquid ones because gases:
a) Are lighter
b) Expand more than liquids
c) Are easier to obtain
d) Don’t change state easily
Answer: b
21. Mercury thermometers work on the principle of:
a) Change in density
b) Expansion of mercury
c) Thermal resistance
d) Change in mass
Answer: b
22. Why does a fan make us feel cool in hot weather?
a) Supplies cold air
b) Cools the air
c) Enhances evaporation of sweat
d) Increases air conductivity
Answer: c
23. Which instrument is used to measure humidity?
a) Kata thermometer
b) Anemometer
c) Sling psychrometer
d) Clinical thermometer
Answer: c
24. A bicycle tyre bursts suddenly due to:
a) Isothermal expansion
b) Adiabatic expansion
c) Isochoric expansion
d) Isobaric expansion
Answer: b
25. Why does a hot glass tumbler break when sprinkled with hot water?
a) Sudden expansion of glass
b) Sudden contraction of glass
c) Water evaporation
d) Chemical reaction with water
Answer: a