Question

Thermal capacity = $mass\times$ heat capacity. (State whether true or false.)
A. True
B. False

Answer 1

The amount of heat energy required to change the temperature of a given body by ${{1}^{\circ }}C$ or ${{1}^{\circ }}K$ is defined as the thermal capacity of the body. Thermal capacity is also called capacity. Specific heat capacity of a body is the heat required to change the temperature of a unit mass of the body by ${{1}^{\circ }}C$ or ${{1}^{\circ }}K$.

Complete answer:
Let us understand what is meant by the heat capacity of a body. We know that when we heat a body, its temperature rises and we cool down the body, its temperature falls down. In other words, if we want to change the temperature of a given body, then we have to either supply heat energy to the body or take out some heat energy from the body.

The amount of heat energy required to change the temperature of a given body by ${{1}^{\circ }}C$ or ${{1}^{\circ }}K$ is defined as the thermal capacity of the body. Thermal capacity is also called capacity.The thermal heat capacity is denoted by ‘C’.Then to understand the relation between heat and change in temperature for a unit mass of the body we define the specific heat capacity of the body (c).

Specific heat capacity of a body is the heat required to change the temperature of a unit mass of the body by ${{1}^{\circ }}C$ or ${{1}^{\circ }}K$.Therefore, the relation between specific heat capacity, heat capacity and the mass of the body is given as $C=mc$.
i.e. Thermal capacity = $mass\times$ specific heat capacity
Therefore, the given statement is false.

Hence, the correct option is B.

Note: Heat capacity and thermal capacity are the same quantities.Suppose a body takes in or given out some heat ‘Q’ and due to this there is a change in its temperature by $\Delta T$, then its thermal capacity of a body is given as,
$C=\dfrac{Q}{\Delta T}$
If the mass of the body is m then its specific heat capacity is given as, $C=mc=\dfrac{Q}{m\Delta T}$