We have seen the Millikan oil drop experiment in the video.
The conclusion of the experiment was:
The charge on the electron = 1.6022 — 10-19C.
Because it was repelling the – ve charged plate, it should be negative.
The magnitude of electric charge q, on the droplets is always an integral multiple of the electric charge, e…..
That is, q = ne, where n = 1, 2, 3