Question

explain how eating effect of electric current depends upon length.​

Answer 1

When current flows through a conductor, heat energy is generated in the conductor. The heating effect of an electric current depends on three factors:

The resistance, R of the conductor. A higher resistance produces more heat.
The time, t for which current flows. The longer the time the larger the amount of heat produced
The amount of current, I. the higher the current the larger the amount of heat generated.
Hence the heating effect produced by an electric current, I through a conductor of resistance, R for a time, t is given by H = I2Rt. This equation is called the Joule’s equation of electrical heating.