Question

why there is no electrical field lines inside a conductor ?

Answer 1

The free electrons constituting the extra charge on a hollow conductor always reside at the surface of the conductor. So, in a charged hollow conductor the charges are always found on its surfaces. Now, when we consider a Gaussian surface within the hollow conductor, there is no charge enclosed by the surface. So, the electric field becomes equal to zero at any point within the charged hollow conductor.

E.ds = 0/ε₀

= > E.ds = 0

= > E = 0 (since, ds has a finite value)

However, in case of a charged solid conductor the electric field within it is not zero.