A thin spherical soap bubble has surface tension S . It's surface is charged with charge Q, its's volume is V it is found that when `Q^(2)=npi varepsilon_(0) SV` the excees pressure inside the bubble becomes zero find n.

Answer

`0096`

Explanation

`V=4/3pir^(3)`….(1)
`sigma=Q/(4pir^(2))` ……(2)
`sigma^(2)/(2in_(0))+p-p_(0)=(4s)/r` …..(3)
`p-p_(0)=0` ….(4)
`Rightarrow 1/(2 in _(0)).Q^(2)/(16pi^(2)r^(4))=(4s)/r`
`Rightarrow 1/(2 in_(0)) . (npi in_(0)s)/(16pi^(2)r^(3)). 4/3 pir^(3)=4s`
`n=96`