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#### Heat and Thermodynamics Two Marks Questions

11th Standard

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Physics

Time : 00:45:00 Hrs
Total Marks : 30
15 x 2 = 30
1. What is Wien’s law?

2. Define thermal conductivity. Give its unit.

3. What is a black body?

4. What is a thermodynamic system? Give examples.

5. What are the different types of thermodynamic systems?

6. What is meant by ‘thermal equilibrium’?

7. An ideal gas is taken in a cyclic process as shown in the figure. Calculate
(a) work done by the gas.
(b) work done on the gas
(c) Net work done in the process

8. For a given ideal gas 6 × 105J heat energy is supplied and the volume of gas is increased from 4 m3 to 6 m3 at atmospheric pressure. Calculate (a) the work done by the gas (b) change in internal energy of the gas (c) graph this process in PV and TV diagram.

9. Suppose a person wants to increase the efficiency of the reversible heat engine that is operating between 100°C and 300°C. He had two ways to increase the efficiency. (a) By decreasing the cold reservoir temperature from 100°C to 50°C and keeping the hot reservoir temperature constant (b) by increasing the temperature of the hot reservoir from 300°C to 350°C by keeping the cold reservoir temperature constant. Which is the suitable method?

10. What is meant by latent heat of vaporization?

11. What is latent heat of sublimation?

12. What is meant by triple point of substance?

13. What is steady state?

14. State Prevost theory of heat exchange.

15. Define Emissivity.