6) that potential is constant
inside the shell (as no work is done in moving a charge inside the shell),
and, therefore, equals its value at the surface, which is
0
1
4
q
V
R
ε
=
π
[2 19(b)]
Example 2 2 Two charges 3 × 10–8 C and –2 × 10–8 C are located
15 cm apart At what point on the line joining the two charges is the
electric potential zero