An ideal gas goes from state A to state B via three different processes as indicated in the P-V diagram. If Q1,Q2,Q3 indicate the heat absorbed by the gas along the three processes and ΔU1,ΔU2,ΔU3 indicate the change in internal energy along the three processes respectively, then
Initial and final condition is same for all process
ΔU1=ΔU2=ΔU3
ΔQ=ΔU+ΔW
Work done ΔW1 > ΔW2 > ΔW3 (Area of P.V. graph)
So Q1 . Q2 > Q3.