Question

The ratio of work done by an ideal monoatomic gas to the heat supplied to it in an isobaric process is:

• A. $\frac{2}{3}$
• B. $\frac{3}{2}$
• C. $\frac{3}{5}$
• D. $\frac{2}{5}$

Answer 1

The correct option is D $\frac{2}{5}$

In isobaric process, heat supplied is $Q=n{C}_P\Delta T$.

Work done is $W=P\Delta V=nR\Delta T$.

Hence ratio is $\frac{R}{C_P}=\frac{R}{\frac{\gamma R}{\gamma -1}}=\frac{2}{5}$ [$\because \gamma =\frac{5}{3}$, for a monoatomic gas]