An electrostatic paint sprayer has a metal sphere of diameter 18 cm and at a potential of 25 kV. The charge on the metal sphere is

Options

A. `0 . 25 mu C`
B. `2 . 5 mu C`
C. `0 . 5 mu C`
D. `25 mu C`

Answer

A

Explanation

Given
Radius of sphere, ` r = (18)/(2) = 9 cm = 9 xx 10^(-2) m `
Potential, `V = 25 kV = 25 xx 10^(3) V `
`V = (kq)/(r)`
Charge, `q = (Vxxr)/(k) = (25 xx 10^(3) xx 9 xx 10^(-2))/(9 xx 10^(9))`
`= 25 xx 10^(-8) c = 0 . 25 xx 10^(-6) C`
`0 . 25 mu C`