Two moles of helium gas undergo a reversible cyclic process as shown in figure. Assuming gas to be ideal, what is the net work involved in the cyclic process?

Wnet = area enclosed V=nRTPVA=2R×3001=600R1VB=2R×3002=300R1;    Vc=2R×4002=400R1  VD=800R1WAB=−nRTTAln⁡VBVA=−2R(300)ln⁡12=600Rln2WBC=−2(400−300)R=−200RWCD=−2R(400)ln⁡VDVC=−800Rln2WAD=−1(600R−800R)=200RWTotal =WAB+WBC+WCD+WAD=200Rln2=−100RIn4