A tiny oil drop of mass carries an unknown number of excess electrons
PHYSICS · Subjective · CBSE · Physics · Electric Charges and Fields · Electric Charges and Fields
Problem
A tiny oil drop of mass 3.0×10−15kg carries an unknown number of excess electrons. It is held stationary between two large horizontal plates that are 1.0cm apart, the upper plate being at a potential of +600V relative to the lower plate.
(a) Calculate the magnitude and direction of the uniform electric field between the plates.
(b) Determine the magnitude and direction of the electric force acting on the oil drop.
(c) Using equilibrium conditions, compute the total charge on the drop and hence find the number of excess electrons it carries.
Take the elementary charge e=1.6×10−19C and neglect air resistance.
Provide all steps clearly, justifying the physical principles invoked.