At a point 20 cm from the centre of a uniformly charged dielectric sphere of radius 10 cm, the electric field is 100 V/m. The electric field at 3 cm from the centre of the sphere will be

Electric field outside of the sphere Eout=kQr2           …(i)Electric field inside the dielectric sphere Ein=kQxR3     …(ii)From (i) and (ii), Ein=Eout×r2xR⇒ At 3cm, E=100×3(20)2103=120V/m