Question

Apply gauss theorem to show that for a spherical shell,the electric field inside the shell vanishes whereas outside it, the field is as if all the charge had been concentrated at the centre

Answer 1

The electric field-lines produced outside even charge distribution point towards the surface of the conductor, in general the end on the excess electrons.

Even the field-lines are normal to the surface as well as it must be the case.

Overall, this process will only cease when the parallel component as well as it can be reduced to zero over the whole surface.