64 drops of the same size are 1 charged to 300 V each. These drops coalesce to form a bigger drop. Calculate the potential of bigger drop.

Explanation

No. of drops = n = 64
Let R= radius of bigger drop p=radius of smaller drop
Q = charge on bigger drop
q=charge on each small drop Potential of each small drop = 300 V
Volume of bigger drop = `nxx` volume of small drop
`rArr (4)/(3)pi^(2)=64xx(4)/(3)pir^(3)`
`rArr R^(3)=64r^(3)`
`rArr R=4r`
Charge on bigger drop `Q=nq=64xxq=64q`
Potential of bigger drop `(1)/(4 pi epsi_(0))(Q)/(R)`
`=(1)/(4pi epsi_(0))((64q))/(4r)`
`=16xx(1)/(4pi epsi_(0))(q)/(r)`
`=16xx` Potential due to small drop
`=16xx300=4800V`