### Thermodynamics

Thermodynamics

These MCQs are intended for checking your Physics subject, Chapter Thermodynamics knowledge.

A Carnot engine whose sink is at 300 K has an efficiency of 40%. By how much should the temperature of source be increased, so as to increase its efficiency by 50% of original efficiency?

A black body at a temperature of 227°C radiates heat at the rate of 20 cal m-2s-1. When its temperature rises to 727°C, the heat radiated will be

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio Cp/Cv for the gas is

A thermodynamical system is changed from state (P1, V1) to (P², V²) by two different processes, the quantity which will remain same is:

The temperatures of inside and outside of a refrigerator are 273 K and 303 K respectively. Assuming, that the refrigerator cycle is reversible, for every joule of work done, the heat delivered to the surrounding will be nearly:

At a given volume and temperature, the pressure of a gas

Which of the following statements is correct for any thermodynamic system?

Which of the following is incorrect regarding the first law of thermodynamics?

A. It is not applicable to any cyclic process B. It is a restatement of the principle of conservation of energy C. It introduces the concept of the internal energy D. It introduces the concept of the entropy

For a diatomic gas change in internal energy for a unit change in temperature for constant pressure and constant volume is U1 and U2 respectively. What is the ratio of U1 and U2?

An engine has an efficiency of 1/6. When the temperature of sink is reduced by 62°C, its efficiency is doubled. Temperature of the source is:

The translational kinetic energy of gas molecules at temperature T for one mole of a gas is

The temperatures of inside and outside of a refrigerator are 273 K and 303 K respectively. Assuming, that the refrigerator cycle is reversible, for every joule of work done, the heat delivered to the surrounding will be nearly:

Which of the following parameters dose not characterize the thermodynamic state of matter?

Heat cannot by itself flow from a body at lower temperature to a body at higher temperature is a statement as a consequence of

In a thermodynamic process, pressure of a fixed mass of the gas is changed in such a manner that the gas molecules give out 30 J of heat. Also, 10 J of work is done on the gas. If the internal energy of the gas was 40 J, what will be the final internal energy?

A Carnots engine works as a refrigerator between 250 K and 300 K. If it receives 750 calories of heat from the reservoir at the lower temperature, the amount of heat rejected at the higher temperature is __________.