Milikans oil drop experiment

Question

please explain relavant to iit jee .

whats it?

Answer 1

Have a look at this link

http://en.wikipedia.org/wiki/Oil-drop_ex...

Answer 2

Wikipedia "oil drop experiment".

Principle: you estimate the weight of an oil drop from its rate of fall against the viscosity of air. You let it pick up an electric charge, and use the field between charged parallel plates to hold it steady. Then charge x field strength balances weight, so you can estimate the charge. This comes in multiples of the charge on an electron.