P-V diagram of a cyclic process ABCA is as shown in the given figure. Choose the correct alternative.

detailed solution

Correct option is A

During process AB pressure and volume both are decreasing. Therefore, temperature and hence internal energy of the gas will decrease (T∝PV) or ΔUA→B=negative. Further, ΔWA→B is negative.In process B to C, pressure of the gas is constant while volume is increasing. Hence, temperature should increase or ΔUB→C = positive. During C to A volume is constant while pressure is increasing. Therefore, temperature and hence internal energy of the gas should increase or ΔUC→A= positive. During process CAB, volume of the gas is decreasing. Hence, work done by the gas is negative.