Question

how does an electric current produce heat?

Answer 1

in metal conductors, electrical current flows due to the exchange of electrons between atoms. As electrons move through a metal conductor, some collide with atoms, other electrons or impurities. These collisions cause resistance and generate heat.

Answer 2

Electric Current is produced due to the flux of electrons that passes through a cross-section.

As electrons flow through wires, they collide with the ions in the wire which causes the ions to vibrate more. This increased vibration of the ions increases the temperature of the wire and thus produces a heating effect.

Heat produced in a conductor (basically wires) is linearly proportional to the current. That is, the more the amount of electrons passes, the more will be heat produced.