Question

What is the cause of resistance in conductors ?

Answer 1

In order to solve this question we need to understand the electric field and the electric force. Electric field or electric line of forces are the forces which a charge produces due to which if any other charge placed in vicinity of this charge it would experience electric force either towards or opposite depending on charge itself. Also whenever there is potential difference across any material then an electric field is produced and it is in the direction of decreasing potential.

Complete answer:
Conductors are materials having free electrons but not organized means they are moving randomly inside the conductor. Now if the conductor is subjected to potential difference then it produces an electric field which in turn exerts electric force on the electrons in the opposite direction.

Now the electrons are organized to a particular direction and this causes electric current to flow in the opposite direction of flow of electrons inside the conductor.Now due to this sudden change in behavior material opposes this and this opposition is known as resistance due to which heat is generated inside the conductor. This is in accordance with Newton's first law which states that any particle subjected to external force would show opposition in its state change known as inertia.

Note: It should be remembered that Conductors are those material having conduction and valence band overlapping with each other so the electrons need not much energy to be free from atoms of conductor whereas in case of dielectric or insulator the gap between valence and conduction band is large so external field need to overcome some energy in order to eject electrons from its metal. This is the reason why conductors are good conductors of electricity while insulators are not.