Question

The ratio of $\frac{C_P}{C_V}$ for a diatomic gas is

• A. $\frac{5}{7} R$
• B. $\frac{7}{9} R$
• C. $\frac{5}{3} R$
• D. $\frac{7}{5} R$

Answer 1

Answer: (D)

$\frac{7}{5} R$

Answer 2

For a diatomic gas
$C_V = \frac{5}{2} R$ and $C_P = \frac{7}{5}R \:\:\:\: \therefore \:\: \frac{C_P}{C_V} = \frac{7}{5}$
In all the options R is given, it should not be there as $C_P/C_V$ is the ratio of two like quantities.