Physics Heat

M.C.Qs on HEAT 1. A large sheet of metal has a hole cut in the middle of it. When the sheet is heated, the area of the hole will a. Not change b. Always increase. c. Always decrease d.Decrease only if the hole is in the exact center of the sheet 2. The surface of a tiled floor normally feels cooler than the surface of a Carpet because a. The tiles are better reflectors of heat than the surface of carpet b. The tiles are better conductors of heat than the surface of carpet c. The tiles have a lower specific heat capacity than the surface of carpet d. The tiles have larger specific heat capacity than the surface of carpet 3. If a liquid contracts on freezing, then the freezing point due to an increase of pressure will. a. increase b. decrease c. remain same d. becomes zero 4. During the change of state, the heat supplied does not change the temperature. It is used in. a. making intermolecular force strong b. changing the pressure c. changing the volume d. weakening the inter molecular force 5. Quantity of heat in a body depends upon its mass temperature and. a. specific heat b. heat capacity c. thermal capacity d. latent heat 6. Mathematically Boyle’s Law is stated as __________. a. PαV b. Pα 7.

d. P=V

Mathematically Charle’s Law is stated as __________. a. VαT b. Vα

8.

1 1 1 c. α V V P 1 V

c. V=T d.

1 1 α V T

Absolute Zero of the temperature is __________. a. 0K

b. 273K

c. -273Kd.

1 K 273

9. “At constant pressure, the temperature of given mass of any gas is directly proportional to the volume of the gas.” This is called __________. a. Boyle’s law b. Charle’s law c. general gas law d. pressure law 10.General gas law is mathematically stated as __________. a. P=VRT b. PT=VnR c. PV=nRT d. PR=nVT 11.the total energy of all the molecules of the substance is known as: (a) temperature (b) specific heat (c) vaporization (d) heat 12. The value of universal gas constant R is given by, in J/kg.K (a) 8314 (b) 83.14 (c) 831.4 (d) 8.314 13. The change in length per unit length per Kelvin rise in temperature is called. a. coefficient of linear expansion b. coefficient of volume expansion. c. coefficient of superficial expansion d. coefficient of geometrical expansion 14. Mathematically co-efficient of linear expansion is written as. a. L= LαΔT b. L= LαΔT c. ΔL= LαΔT d. L= 1+LαΔT 15. Coefficient of cubical expansion in terms of co-efficient of linear expansion is written as. a. β=3α b. 3β=α c. β=3/α d. 1/β=3α

16. The amount of heat required to raise the temperature of 1.0kg of a substance through 1k is called. a. specific heat b. heat capacity c. thermal capacity d. latent heat 17. One Kilowatt-hour (kWh) is equal to. a. 3.6x106 J b. 36x106 J c.0.36x106 J d. 36.3x106 J 18. On increasing the pressure, boiling point of a liquid. a. Decreases b. Increases c. Remain constant d. First increases then decreases 19. At a latent heat the temperature of the substance a. Changes and the state also changes. b. Increases and the state remains same. c. Does not change but the state changes. d. Ddeecrease and state changes. 20. The amount of heat required to melt 1kg of ice at its melting point without changing the temperature is called. a. Heat Capacity b. Specific Heat c. Latent Heat of Fusion of Ice d. Latent Heat of Vaporization 21. Heat produced on account of friction is transferred by a. Conduction b. Convection c. Radiation d. All of the above 22. Heat transfer without medium due to (a) Conduction (b) Convection (c) Radiation

(d) None

23. 12000j of heat energy raises the temperature of a 2kg block of a metal from 200c to 300c. what is the specific heat capacity of the metal (a) 200j/kg 0c (b) 600j/kg 0c (c) 300j/kg 0c (d) 400j/kg 0c 24. Which property of a block of metal remains constant. When the metal is heated ? (a) Length (b)mass (c)volume (d) surface area 25.Which of the following is the poorest conductor of heat energy (a)air (b) water (c) brass (d) vacuum 26. If heat energy is removed from an object its temperature normally (a)fall (b)rise (c) fall then rise (d)stay the same 28. Which instrument can give a reading of 240c (a)an ammeter (b) thermometer (c) barometer (d) micrometer 29. The air in a large paper bag is heated, the bag is then found to rise through the surrounding cold air . this is because: (a) air in the bag has become less dense (b) the mass of the paper bag has decreased (c) heat always rises(d) the mass of the air in the bag has increased. 30. If a temperature difference is 200c. convert it into Fahrenheit. (a) 300c (a) 450c (a) 360c (a) 580c