Eight spherical liquid drops join to form a large drop. Diameter of each drop is 2mm and charge `5mu` statC. What is the potential on the surface of the large drop?

Explanation

Radius of a small drop, r = 1mm = 0.1 cm
Suppose, radius of the large drop is R.
`(4)/(3)piR^3 = 8xx(4)/(3)pir^3" or "R = 2r= 2xx0.1 = 0.2` cm
Capacitance of large drop, C = R = 0.2 statF
Total charge of the small drops,
`Q= 8xx5 = 40 mu statC = 40 xx 10^(-6)` statC
Potential on the surface of the large drop,
`V = (Q)/(C )=(40xx10^(-6))/(0.2)` statV `=2xx10^(-4)xx300V= 0.06V`.