Heat & Thermodynamics Test Online MCQs

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

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

3. In an adiabatic change, the pressure and temperature of a monoatomic gas are related with relation as P ∞ T^C, where C is equal to:

4. 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:

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

6. The colour of a star indicates its:

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

8. 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:

9. The absolute zero is the temperature at which

10. 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?

11. 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:

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

13. 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:

14. Fraunh offer line of the solar system is an example of:

15. 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