If the electric potential of the inner shell is $10\text{V}$ and that of the outer shell is $5\text{V}$, then the potential at the centre will be

The correct option is A $10\text{V}$
We know that, from centre to the surface of the inner shell, potential will remain constant.
Therefore, potential at centre of the shell will be equal to $10\text{V}$.

Concept- Electric potential on the surface and at any point inside the shell is equal.