The graph given below shows heat energy supplied against change in temperature when no energy is lost to the surrounding. The slope of this graph will give :

Heat capacity

Reason — When no energy is lost to the surrounding, the amount of heat energy supplied is directly proportional to the change in temperature △t i.e.

$$\begin{aligned}\text Q ∝ △\text t\\[1em] \text {or} \\[1em] \text Q = \text {mc} △\text t\end{aligned}$$

Where,

m : mass of a substance

c : specific heat capacity of the substance

So,

$$\begin{aligned}\frac {\text Q}{△\text t} = \text {mc} \\[1em] \text {Slope of Q vs △\text t graph} = \frac {\text Q}{△\text t} = \text {mc}\end{aligned}$$

And mc is the heat capacity (C) of the body

Hence, slope of Q vs △t graph gives the value of the heat capacity.