Answer this question. I`m getting confused very much

Dear student,

The electric field inside a conductor is always zero. When there is an external electric field, electric field is induced in the direction opposite to that of external electric field and of same magnitude so that net electric field inside it is zero.

The electric field at the center of sphere due to the charge is

Hence the induced electric field at that point is

However potential at that point due to the charge is simply given by