State Joule's law of heating.

Explanation

If current I flows through a conductor kept across a potential difference V for a time t, the work done or the electric potential energy spent is
`W=Vit`
In the absence of any other external effect, this energy is spent in heating the conductor. The amount of heat (H) produced is
`H=VIt`
For a resistance R,
`H=I^(2)Rt`
This relation was experimentally verfied by Joule and is known as Joule's law of heating. It sates that the heat developed in an electricall circuit due to the flow of current varies directly as
(i) the square of the current
(ii) the resistance of the circuite and
(iii) the time of flow.