why is heat produced in a conducted due to flow of electric current?

Question

anonymous · Answer

Good question tuba,
      Electric current is caused due to the flow of electrons called valence electrons. We have another group of electrons called stationary electrons that are are strongly bounded to nucleus in an atom and will not participate in electric current conduction. While in the conduction process if these valence electrons collide with stationary electrons, energy is produced in the form of heat.

anonymous · Answer

they also collide with the nucleus also?

anonymous · Answer

Dear Abishek Electron will never collide with Nucleus. When electrons get near by nucleus, they take position into orbits around the nucleus. Only neutron can collide with nucleus. When it happens it leads to Big explosion called Nuclear explosion by Releasing Huge amount of energy.   This mechanism what we call as Nuclear Fission. Eg: Nuclar Bomb or Atomic bomb.