Question

Calculate magnitude of total work done (in atm.lit) for the above process $ABCD$ involving a monoatomic ideal gas.
$[Given:ln2=0.7]$

Answer 1

$A\to B$ is an isobaric process

$\therefore \left|W_{AB}\right|=P_A(V_B-V_A)$

$=1\times (10-5)$

$=5$ atm.lit

$B\to C$ is an isothermal process.

$\therefore \left|W_{BC}\right|=nRTln\frac{V_2}{V_1}$

$=n0.082\times \frac{P_1{V}_B}{nR}ln\frac{V_C}{V_B}$

$=1\times 10\times ln\frac{20}{10}$

$=10\times 0.7$

$=7$ atm.lit

$C\to D$ is an isobaric process

$\therefore \left|W_{co}\right|=\left|P_2(V_D-V_c)\right|$

$=|\frac{1}{2}\times (10-20)|$

$=5$ atm.lit

$\therefore$ Magnitude of total work done$=5+5+7$

$=17$ atm.lit