A soap bubble (surface tension T) is charged to a uniform charged density `sigma`. At equilibrium the radius of the bubble is given by `(Nepsilon_(0)T)/(sigma^(2))`. The value of N is [Assume that atmosphere is not present]

Answer

8

Explanation

At equilibrium just before bursting the force due to surface tension is balanced by electrostatic
repulstion so `(4T)/(r)xx"area"=(sigma^(2))/(2epsilon_(0))xx"area"impliesr=(8epsilon_(0)T)/(sigma^(2))`