- Home
- Standard 11
- Physics
11.Thermodynamics
normal
An ideal gas expands isothermally from a volume $V_1$ to $V_2$ and then compressed to original volume $V_1$ adiabatically. Initial pressure is $P_1$ and final pressure is $P_3$ . The total work done is $W$ . Then
A
$P_3 > P_1, W > 0$
B
$P_3 < P_1, W < 0$
C
$P_3 > P_1, W < 0$
D
$P_3 = P_1, W = 0$
Solution
From graph it is clear that $P_{3}>P_{1}$
since area under adiabatic process $(BCED)$ is
greater than that of isothermal process $(ABDE).$
Therefore net work done
$\mathrm{W}=\mathrm{W}_{\mathrm{i}}+\left(-\mathrm{W}_{\mathrm{A}}\right) \because \mathrm{W}_{\mathrm{A}}>\mathrm{W}_{\mathrm{i}} \Rightarrow \mathrm{W}<0$
Standard 11
Physics
