Question

A thin metallic spherical shell contains a charge $Q$ on its surface. A point charge $q_1$ is placed at the centre of the shell and another charge $q_2$ is placed outside the shell. All the three charges are positive. Then, the force on charge $q_1$ is

• A. Towards left
• B. Towards right
• C. Upward
• D. Zero

Answer 1

The correct option is D Zero

$\text{Step 1: Electrostatic Shielding}$

Due to Electrostatic shielding, The metallic spherical shell acts as a shield and do not allow the electric field due to outside charges to penetrate through it.

Hence, electric field inside shell due to $Q$ and $q_1$ is zero.

Therefore, no force will act on charge $q$.

Hence, Correct answer is $\left(D\right)$

$\text{Note :}$ Electrostatic shielding acts in case of closed metallic surfaces with cavity in which external field does not effect internal contents and internal field does not effect external contents.