Class 11 NEET Physics Thermodynamics and Kinetic Theory

In a cyclic process,ΔU=0 In a cyclic process work done is equal to the area under the cycle and is positive if the cycle is clockwise and negative if anticlock wise
∴ΔW=− Area of rectangle ABCD=−P(2V)=−2PV
According to first law of thermodynamics
ΔQ=ΔU+ΔW or ΔQ=ΔW
(As ΔU=0)
i.e., heat supplied to the system is equal to the work done
So heat absorbed, ΔQ=ΔW=−2PV
∴ Heat rejected by the gas = 2PV