The strength of electric filed in the charged and isolated capacitor is decreased when the dielectric slab is inserted.
When the dielectric slab is inserted between the plates of a charged capacitor, electricfield produced due to induced charged, opposite to the external field.

Options

A. Both A and R false
B. Both A and R true and R is not correct reason for A
C. A is true and R is false
D. Both A and R are true and R is correct reason of A.

Answer

D