Which one of the following statements best defines the concept of heat?

Question

Question

This question was previously asked in

NDA-II 2024 (GAT) Official Paper (Held On: 01 Sept, 2024)

Answer 1

CONCEPT:

Heat

Heat is a form of energy transfer between systems or objects with different temperatures (thermal energy in transit).
It always flows from the hotter object to the cooler one, until thermal equilibrium is reached.
The SI unit of heat is the joule (J), but it is also commonly measured in calories (cal).

EXPLANATION:

Among the given options:
- Option 1: "The transformation of energy from one form to another" is not specific to heat, as it applies to energy in general.
- Option 2: "The conversion of energy into mass and vice-versa due to temperature difference" refers to a relativistic concept (E=mc²), not heat transfer.
- Option 3: "The transfer of energy due to temperature difference" accurately describes heat.
- Option 4: "The change in volume of a substance with temperature" refers to thermal expansion, not heat itself.

Therefore, the best definition for heat among the options provided is The transfer of energy due to temperature difference.