A point charge +Q is kept at distance 3a from the centre of a spherical conducting shell of radius a carrying charge -3Q. Taking k = 1/(4πε₀), select the correct statement(s).

Select all that apply

• Option A

  Before closing the switch, the electric field at C due to the shell is -(kQ/9a²)$\hat{i}$.

• Option B

  Before closing the switch, the potential of the shell is -8kQ/(3a).

• Option C

  After closing the switch, the charge on the shell is -Q/3.

• Option D

  After closing the switch, the charge on the shell is zero.