- Home
- Standard 11
- Physics
One mole of a monoatomic gas and one mole of a diatomic gas are initially in the same state. Both gases are expanded isothermally and then adiabatically, such that they acquire the same final state. Choose the correct statement.
Work done by diatomic gas is more than that by monoatomic gas
Work done by monoatomic gas is more than that by diatomic gas
Work done by both the gases are equal
Change in internal energies of both the gases are equal
Solution
$(a)$ Expansion curves are as shown below.
As, slope of an adiabatic curve $=-\gamma\left(\frac{p}{V}\right)$
Also, $\gamma_{\text {diatomic }}\left(=\frac{7}{5}\right) < \gamma_{\text {monoatomic }}\left(=\frac{5}{3}\right)$
So, adiabatic expansion will be more stecp for monoatomic gas, whereas isotherms for both gases are nearly same. As, work done $=$ area under $p-V$ graph
$\therefore$ Work done is more for diatomic gas.
