A spherical metal body has +Q charge, uniformly distributed over its outer surface. The body has a cavity at its centre. Select proper procedure from those given below which will change the charge on the outer surface of this body from +Q to –Q.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Charge –2Q is inserted in the cavity and is kept insulated from the inner surface of the cavity
Now to change net charge on outer surface of sphere as –Q. Place a charge –2Q at centre of sphere without making a contact with sphere.