Question

In an experiment replicating Millikan’s oil drop experiment, a pair of parallel plates are placed 0.0200 m apart and the top plate is positive. When the potential difference across the plates is 240.0 V, an oil drop of mass 2.0 × 10-11 kg gets suspended between the plates. (e = 1.6 × 10-19 C)


(a) What is the charge on the oil drop?

(b) Is there an excess or deficit of electrons on the oil drop? How many electrons are in excess or deficit?

Answer 1

(a) The charge on the oil drop is 1.5 × 10-19 C.

(b) There is an excess of electrons on the oil drop. There are 9.375 × 1010 electrons in excess.