Question

Which one is correct about given P - V plot for 2 mole an ideal gas ?

• A. $W_{AB}=-20L-atm$
• B. $\Delta U$ for Cycle = 0
• C. $\Delta S_{Cycle}=0$
• D. $W_{CA}=+13.86Latm$

Answer 1

The correct option is A $W_{AB}=-20L-atm$

$\left(A\right)$ $W_{AB}=-P_{ext}(V_2-V_1)=-1(40-20)=-20$ $I-atom$

$\left(B\right)$ $\Delta U$ for cycle $=0$ (As initial and final temperatures are same).

$\left(C\right)$ $\Delta S=nR\ln \left(\frac{V_2}{V_1}\right)+n{C}_V\ln \left(\frac{T_2}{T_1}\right)$

As initial and final states are same: $\Delta S=0$

$\left(D\right)$ Workdone in $AC=$ Workdone in $ABCA-$ Workdone in $AB=\frac{\pi \times 0.5\times 20}{4}-20=-12.15$ $L-atm$

Workdone in $CA=12.5$ $L-atm$