Question

There are two charged sphere of radius R and 3R. When the sphere are made to touch each other and then separate, the surface charge density becomes \(r_1\) and \(r _2\) respectively. Find \(\frac{r_1}{r_2}\)

(1) \(\frac{1}{9}\)

(2) \(\frac{1}{3}\)

(3) 3

(4) 9

Answer 1

Correct option is : (3) 3

We know finally the potential will be same.

So, \(\delta _1 r_1 = \delta _2 r_2\)

\(\Rightarrow \ \delta _1R = \delta _2.3R\)

\(\Rightarrow \frac{\delta _1}{\delta _2} = 3\)