UPSC NDA I 2018 General Ability Solved Paper

Concept:Thermal capacity (heat capacity) is the amount of heat required to raise the temperature of a body by $1^\circ\text{C}$ (or $1\ \text{K}$).It is given by $C = \frac{Q}{\Delta T} = mS$, where $m$ is mass and $S$ is specific heat capacity of the material.Explanation:• Thermal capacity is an extensive property – it directly depends on the mass of the body.• For a given material, $S$ is constant, so $C$ varies only with $m$.• Shape of the body does not affect thermal capacity; it is the same for every molecule.• Density is not a factor because thermal capacity is a property of the material, not its compactness.• Temperature change is the effect, not the cause – the definition uses a unit temperature change, so $C$ itself does not depend on the current temperature.• Therefore, among the given options, thermal capacity depends only on the mass of the body.Answer:A. Mass of the body only