Question

An ideal gas expands isothermally from volume `V_(1)` to `V_(2)` and is then compressed to original volume `V_(1)` adiabatically. Initialy pressure is `P_(1)` and final pressure is `P_(3)`. The total work done is `W`. Then
A. `P_3 gt P_1,W gt 0`
B. `P_3 lt P_1,W lt 0`
C. `P_3 gt P_1,W lt 0`
D. `P_3=P_1,W=0`

Answer 1

Correct Answer - C

`(P_1,V_1)overset(isothermal)to(P_2,V_2)overset(adiabatic)to(P_3,V_1)`
`P_3gtP_1`
`DeltaW_(1rarr2)=+ve,DeltaW_(2rarr3)=-ve`
`|DeltaW_(2rarr3)|gtDeltaW_(1rarr2)`
`W=DeltaW_(1rarr2)+DeltaW_(2rarr3)=-ve`
`Wlt0`