Question

When an electric current is passed through an electric bulb, it becomes warm when touched. Give reasons.

Answer 1

When an electric current is passed through an electric bulb, energy is dissipated in form of heat due to its resistance, that's why it becomes warm when touched.

Amount of heat dissipated when $I$ current follow through resistance $R$ in time $t$.

$\Rightarrow H=I^{2}Rt$