Question

The densities of two substances are in the ratio $3:4$ and their specific heats are in the ratio $2:3$. The ratio of thermal capacities per unit volume of these substances is

• A. 2 : 3
• B. 3 : 4
• C. 1 : 1
• D. 1 : 2

Answer 1

Answer: (D)

1 : 2

Thermal capacity$=$mass$\times$specific heat
Thermal capacity per unit volume$=$density$\times$specific heat
$\Rightarrow \frac{C_1}{C_2}=\frac{{\rho }_1}{{\rho }_2}.\frac{c_1}{c_2}$
$\frac{C_1}{C_2}=\frac{3}{4}.\frac{2}{3}=1/2$
Option D.