Question

The ratio of densities of two substances is 2 : 3 and that of specific heats is 1 : 2. The ratio of thermal capacities per unit volume is

• A. 1 : 2
• B. 2 : 1
• C. 1 : 3
• D. 3 : 1

Answer 1

Answer: (C)

1 : 3

Thermal capacity per unit volume$\left(C^{\prime }\right)=$Heat capacity/volume
$\frac{C_1^{\prime }}{C_2^{\prime }}=\frac{C_1/V_1}{C_2/V_2}$
$\frac{C_1^{\prime }}{C_2^{\prime }}=\frac{C_1}{C_2}\times \frac{V_2}{V_1}$
$\frac{C_1^{\prime }}{C_2^{\prime }}=\frac{C_1}{C_2}\times \frac{{\rho }_1}{{\rho }_2}=\frac{1}{2}\times \frac{2}{3}=\frac{1}{3}$
Option C.