18. An electric dipole is completely inside a closed imaginary surface and there are no other charges. True or false: (a) The electric field is zero everywhere on the surface. (b) The electric field is normal to the surface everywhere on the surface. (c) The electric flux through the surface is zero. (d) The electric flux through the surface could be positive or negative. (e) The electric flux through a portion of the surface might not be zero

We shall apply Gauss's theorem to calculate the electric flux through a closed surface due to charge contained in side

Total charge inside surface = zero

So total electric flux through closed surface will be zero.

or electric flux going out = electric flux coming in

(a) The electric field is zero everywhere on the surface. True

(b) The electric field is normal to the surface everywhere on the surface. - false

(c) The electric flux through the surface is zero. True

(d) The electric flux through the surface could be positive or negative - false

(e) The electric flux through a portion of the surface might not be zero - True