An isolated conducting sphere of radius R carries a charge Q. The electric potential at its centre is (V(∞) = 0)

1. By your syllabus result 4 of §2.9, V is constant throughout a conductor in electrostatics. 2. The value at the centre equals the value at the surface = kQ / R. 3. (A) confuses E (=0 inside) with V; (C) is the field, not the potential. _Source: syllabus Physics Part I, Ch 2 §2.9 result 4_