Question

(1): The strength of the electric field in the charged and isolated capacitor is decreased when the dielectric slab is inserted.

(2): When the dielectric slab is inserted between the plates of a charged capacitor, the electric field produced due to induced charge, opposite to the external field.

• A. Both 1 and 2 false
• B. Both 1 and 2 true and 2 is not correct reason for 1
• C. 1 is true and 2 is false
• D. Both 1 and 2 are true and 2 is correct reason of 1.

Answer 1

The correct option is D Both 1 and 2 are true and 2 is correct reason of 1.

When a dielectric slab is inserted between the charged plates of a capacitor, polarisation of the dielectric slab occurs, due to this an internal electric field is generated in slab in the direction opposite to that of between the plates of capacitor. Hence electric field between the plates decreases due to field produced in slab. Therefore both assertion and reason are correct and R is correct reason of A.