Two thin concentric conducting shells of radii R and 2R are shown in figure. The outer shell carries a charge +Q and inner shell is neutral. Choose the correct option(s) :-

When switch S is closed, potential of inner sphere becomes zero.

With switch S closed charge on inner sphere is (-Q).

With switch S closed charge on inner sphere is $(-\frac{\mathrm{Q}}{2})$.

With switch S is open, potential of inner sphere is same as that of a point at distance $\frac{3\mathrm{R}}{2}$ from centre.