Question

Electric Potential 9-2 1) Picture a conducting sphere with a net positive charge on its surface. Discuss the followin estions with your lab partners. a) Why must all of the excess charge on the conductor reside on the surface of the sphere? b) We know that at equilibrium the electric field inside the conductor must be zero. Does this mean that the electric potential inside the sphere is zero? c) Is the potential changing inside the conducting sphere? d) How does the potential change as you move further and further from the sphere?

Answer 1

(a) The entire positive charge reside on the outer surface, because positive charges repel each other, and therefore reaches the maximum distance apart, which is the surface of the conductor.

(b) Electric Field inside the conductor is zero, which indicates the electric potential is uniform throughout the conductor i.e. electric potential at any point inside the sphere is same as that on the surface of the sphere.

(c) No, potential is same everywhere inside the conductor.

(d) At points outside the sphere, electric potential is given as:

V = kq/r

where, ''q'' is the charge of the sphere, and ''r'' is the distance from the center of the sphere.