**1. The problem statement, all variables and given/known data**

A particle having charge q = 8.85 μC is placed on the axis of a circular ring of radius R = 30 cm. Distance of the particle from centre of the ring is a = 40 cm. Calculate electrical flux passing through the ring.

**2. Relevant equations**

Flux through a closed surface = q/ε

**3. The attempt at a solution**

I have tried to sketch a figure .

Since the circle is not a closed surface .I tried to make the spherical cap whose base is the given circle . Then I completed that sphere .

Now I think flux through the circle is equal to the flux through the spherical cap .But then what is the flux through the spherical cap ?

Is the ratio of the surface area of the cap to that of the sphere same as the ratio of the flux across these two surfaces ?

I would appreciate if somebody could help me with the problem .

http://ift.tt/1fFqYp3