Question

A spherical conductor has a radius of 14.0 cm and a charge of 26.0 µC.

Calculate the electric field and the electric potential at:

(a) r = 10.0 cm,

(b) r = 20.0 cm,

(c) r = 14.0 cm from the center.

Answer 1

For a spherical conductor, the electric field inside the conductor is zero. And the electric potential inside the sphere is equal to the electric potential at the surface of the conductor. At for a point outside the sphere, the electric field and electric potential is given by that of a point charge at the center of the sphere.
So, for the sphere of radius R = 14.0 cm, and charge Q = 26.0 microcoulombs,
a)
  At r = 10.0 cm < 14.0 cm,
   the electric field is zero.
The electric potential is given by
  

  

b)
  At r = 20.0 cm > 14.0 cm,
   the electric field is




The electric potential is given by
  

  

c)
  
  At r = 14.0 cm = R
   the electric field is



The electric potential is given by