Question

A monoatomic gas expands isobarically. Find the ratio of the percentages of heat supplied, that increases the thermal energy and that is involved in doing work for expansion.

Answer 1

For an isobaric process, $Q=n{C}_p\Delta T$

and $W=nR\Delta T$

Now, $C_p=\frac{\gamma R}{\gamma -1}$ [ for an isobaric process]

$\frac{\Delta W}{\Delta Q}=\frac{R}{C_p}=\frac{\gamma -1}{\gamma }$

For monoatmic gases , $\gamma =3$

$\therefore \frac{\Delta W}{\Delta Q}=\frac{\gamma -1}{\gamma }=\frac{\frac{5}{3}-1}{\frac{5}{3}}=0.4=40\%$