Question

An isolated and charged spherical soap bubble has a radius r and the pressure inside is atmospheric. If t is the surface tension of soap solution, the charge on the drop is

Answer 1

Explanation:

Since air pressure inside and outside is equal, Surface tension will be balanced by electrostatic pressure.

4T/r = sigma / 2 e°

sigma = surface charge density = q / 4πr^2

e° is epsilon constant