The potential of a uniformly charged spherical shell at a point r/2 from its centre is 5 V. The potential at its surface is: (Given radius of shell = r)

5 V

The correct answer is Option (3) → 5 V

The potential at any point inside the spherical shell (i.e., at $r=r/2$) is the same as the potential on the surface of the shell. This is because, it is a equipotential surface.

Thus, the potential at the surface of the spherical cell = 5V