Heat & Thermodynamics Test Online MCQs

1. The surface temperature of a body is 727°C and that of another body is 327. The ratio of total energies radiated by them is:

2. The instrument used to measure the temperature of the source from its thermal radiation is:

3. 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:

4. When a solid is converted into a gas, directly by heating then this process is known as:

5. On a cold morning, a metal surface on touching is felt colder than a wooden surface, because the metal has:

6. A quantity of heat required to change the unit mass of a solid substance to its liquid state, while the temperature remains constant, is known as

7. Woolen clothes keep the body warm because the wool:

8. The absolute zero is the temperature at which

9. A black body is heated from 27°C to 127°C. The ratio of their energies of radiation emitted will be:

10. Heat travels through vacuum by:

11. 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:

12. Which one of the following is not a thermodynamical co-ordinate?

13. The density of a substance at 0°C is 10 g/cc and at 100°C, its density is 9.7 g/cc. The coefficient of linear expansion of the substance 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. Fraunh offer line of the solar system is an example of: