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, then charge on drop is:

Options

A. `2sqrt((2rT)/(epsilon_(0)))`
B. `8pirsqrt(2r T epsilon_(0))`
C. `8pirsqrt(r T epsilon_(0))`
D. `8pirsqrt((2rT)/(epsilon_(0)))`

Explanation

(B) Inside pressure must be `(4T)/r` greater than outside outside pressure is provided by charge on bubble.
`(4T)/r=(sigma^(2))/(2epsilon_(0))`
`(4T)/r=(Q^(2))/(16pi^(2)r^(4)xx2epsilon_(0))........[sigma=Q/(4pir^(2))]`
`Q=8pirsqrt(2rTepsilon_(0))`