Question

A charge q=10muC is distributed uniformly over the circumference of a ring of radius 3m placed on x-y placed with its centre art origin. Find the electric potential at a point P(0,0,4m)

Answer 1

Given :

A charge q = 10 $\mu$C is distributed uniformly over the circumference of a ring

The radius of the ring = 3 m

The ring is placed on x-y axis

To Find :

The electric potential at point P ( 0 , 0 , 4 )

Solution :

Potential at any point is given as V = $\dfrac{1}{4\Pi \varepsilon _o}$ × $\dfrac{q}{d}$

where d is the distance of point P from circumference of ring

And   $\dfrac{1}{4\Pi \varepsilon _o}$  = 9  ×$10^{9}$

Now,

Distance = d = $\sqrt{3^{2} +4^{2} }$

                    = √25  = 5  m

So,     V = 9 ×$10^{9}$  ×  $\dfrac{10\times 10^{-6}}{5}$

Or,     V = 18000

∴  Potential= V = 1.8 × $10^{4}$  volt

Hence,  The electric potential at a point P ( 0, 0 , 4 m ) is  1.8 × $10^{4}$  volt  Answer