A charged plastic spherical ball of mass `8.4 xx 10^(-14) kg` is found to remain suspended in a uniform electric field of Entensity `5 xx 10^2 NC^(-1)`. Calculate the charge on the ball.

Explanation

` m = 8.4 xx 10^(-14)` kg
`E = 5 xx 10^2 NC^(-1)`
Let q = charge on the ball
Ball will remain suspended only when Electric force acting in upward direction= Weight of the ball in downward direction.
`qE = mg`
`q = (mg)/E`
`q = (8.4 xx 10^(-14) xx 9.8)/(5 xx 10^2)`
`q = 16.46 xx 10^(-16) C`
or `q = 1.65 xx 10^(-15) C`