The earth has a downward-directed electric field near its surface of about 150 n> c. if a raindrop with a diameter of 0.020 mm is suspended, motionless, in this field, how many excess electrons must it have on its surface?

Explanation:

A rain drop has diameter given as

so the radius of the rain drop will be

now the volume of the rain drop is given as

now weight of the rain drop is given as

now this weight of the rain drop is counterbalanced by force due to electric field

so we have

well clustered together.

points close on a scatter diagram