Question
Physics Question on Thermodynamics
If the ratio of densities of two substances is 5:6 and the ratio of their specific heat capacities is 3:5, then the ratio of heat energies required per unit volume so that the two substances can have same temperature rise is:
A
1:1
B
1:4
C
1:2
D
1:3
Answer
1:2
Explanation
Solution
The correct option is: 1:2.
The ratio of densities for the two substances is 5:6, and the ratio of their specific heats is 3:5. Thermal capacity can be represented as the product of specific heat and mass, where mass is calculated using density and volume. The thermal capacity per unit volume (T) is given by the product of density (ρ) and specific heat (C).
The ratio can be expressed as:
T₂ / T₁ = ρ₂ * C₂ / ρ₁ * C₁ = (6 * 5) / (5 * 3) = ½=1:2