Heat & Thermodynamics Test Online MCQs

1. A centigrade and Fahrenheit thermometers are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers a temperature of 140° the fall of the temperature as registered by the centigrade thermometer is:

2. A black body, at a temperature of 227°C, radiates heat at a rate of 20 cal m⁻²s⁻¹. When its temperature is raised to 727°C, the heat radiated by it in cal m⁻²s⁻¹ will be closest to:

3. An ideal gas at 27°C is compressed adiabatically to 8/27 its original volume [TV^γ-1 = constant] and γ = 5/3, then the rise in temperature will be:

4. The volume of a gas is reduced adiabatically to (1/4) of its volume at 27°C. If γ = 1.4. The new temperature will be:

5. A black body is at a temperature 300 K. It emits energy at a rate, which is proportional to:

6. The latent heat of vaporization water is 2240 J. If the work done in the process of vaporization of 1g is 168 J, then increase in internal energy is:

7. The average kinetic energy of a gas molecule at 27°C is 6.21 x 10⁻²¹J, then its average kinetic energy at 227°C is:

8. The real coefficient of volume expansion of glycerine is 0.000597 per °C and linear coefficient of expansion of glass is 0.000009 per °C. Then the apparent volume coefficient of expansion of glycerine is:

9. During the adiabatic expansion of a gas the internal energy of a gas is found to decrease by 2 joule. The work done on gas during the process will be equal to:

10. The colour of a star indicates its:

11. If the temperature of a black body increase from 7°C to 287°C, then the rate of emission of radiation energy is:

12. The radiation from the sun, incident normally at the surface of the earth is 20kcal/m² min. What would have the radiant energy, incident normally on the earth of the sun had a temperature, twice of the present one?

13. In an adiabatic process the quantity which remains constant is:

14. The relative humidity on a day, when partial pressure of water vapour is 0.012 x 10⁵ pa at 12°C is (take vapour pressure if water at this temperature as 0.016 x 10⁵ pa)

15. A sample of gas expands from volume V₁ to V₂. The amount of work done by the gas is greatest, when the expansion is: