In Millikan’s oil drop experiment an oil drop carrying a charge Q is held stationary by a p.d. 2400 v between the plates. To keep a drop of half the radius stationary the potential difference had to be made 600 v. What is the charge on the second drop ?
Options:
(a) `(3Q)/ 2`
(b) `Q/ 4`
(c) Q
(d) `Q /2`