A dielectric slab A. Q’ may be larger than Q.

B. Q’ must be larger than Q.

C. Q’ must be equal to Q.

D. Q’ must be smaller than Q.

When a dielectric slab of dielectric constant K is introduced between the plates of the capacitor, the net electric field in the dielectric becomes

Where,

E₀ is the electric field when there is vacuum between the plates.

K is the dielectric constant of the dielectric

The net electric field is due to charges +Q, -Q and due to induced charges +Q’,-Q’in opposite direction).

So, the net electric field becomes

Where,

Q’=induced charge due to dielectric

Q=charge on the capacitor in vacuum

K=dielectric constant

Since dielectric constant K>1

Q’<Q

Therefore, on inserting a dielectric slab between plates of capacitor the induced charge Q’ is less than Q.