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

detailed solution

Correct option is D

During process A to B, 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 also negative as the volume of the gas is decreasing. Thus, ΔQA→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.