Question

A charge q is uniformly distributed on a ring of radius r. A sphere of an equal radius is constructed with its centre lying on the periphery of the ring. The flux of electric field through the surface of the sphere will be

(a) q/ε₀

(b) _q/2ε0

(c) q/3ε₀

(d) q/4ε₀

Answer 1

Correct option (c) q/3ε₀

Explanation:

Charge on ring = q,

Centre of ring = O

Centre of sphere = O'

Linear charge density of ring,

Charge on arc AB of ring,

i.e., charged enclosed by sphere = q/3

.'. Flux coming out of sphere = q/3ε_0.