Thermal capacity of a body depends on the

Thermal capacity of a body depends on the

mass of the body only
mass and shape of the body only
density of the body
mass, shape and temperature of the body
This question was previously asked in
UPSC NDA-1 – 2018
The correct answer is A.
Thermal capacity (or heat capacity) of a body is the amount of heat energy required to raise its temperature by one degree Celsius (or Kelvin). It is an extensive property, meaning it is proportional to the amount of substance. Specifically, Thermal Capacity (C) = mass (m) ร— specific heat capacity (c). The specific heat capacity (c) is an intensive property that depends on the material of the body.
Looking at the options:
A) mass of the body only: While incomplete as it doesn’t mention the material (specific heat capacity), mass is a fundamental determinant.
B) mass and shape of the body only: Shape does not affect thermal capacity. Incorrect.
C) density of the body: Density is mass per unit volume. Thermal capacity depends on total mass, not density directly unless volume is fixed and material is implied. Incorrect.
D) mass, shape and temperature of the body: Shape is incorrect. While specific heat capacity can vary with temperature, “temperature of the body” in this context is ambiguous and shape is explicitly wrong. Incorrect.
Given the options, A is the best fit as mass is a primary factor, even though the material’s specific heat capacity is also crucial. The question asks what it “depends on” among the options provided. Mass is the only consistently correct factor listed without incorrect additions in options B, C, and D. This suggests the question focuses on the extensive nature of thermal capacity.
The specific heat capacity ‘c’ is a property of the material and represents the heat capacity per unit mass. The thermal capacity ‘C’ of a body is the total heat capacity for that specific body, which is the product of its mass and the specific heat capacity of the material it’s made from.