Question
Physics Question on electrostatic potential and capacitance
A charge + q is fixed at each of the points x=x0,x=3x0,x=5x0...8 on the x-axis and a charge - q is fixed at each of the points x=2x0,x=4x0,x=6x0...,8 Here, x0 is a positive constant. Take the electric potential at a point due to a charge Q at a distance r from it to be Q/4pε0r. Then the potential at the origin due to the above system of charges is
A
zero
B
8pε0x0In2q
C
infinite
D
4pε0x0qIn2
Answer
4pε0x0qIn2
Explanation
Solution
Potential at origin will be given by
V=4pε0q[x01−2x01+3x01−4x01+....]
=4pε0q.x01[1−21+31−41+....]=4pε0x0qIn(2)