A particle A having charge of `2.0xx10^-6C` and a mass of 100 g is fixed at the bottomk of a smooth inclined plane of inclination `30^@`. Where should another particle B having same charge and mass, be placed o the inclined plane so that B may remain in equilibrium?

Options

A. 8 cm from the bottom
B. 13 cm from the bottomk
C. 21 cm from the bottom
D. 27 cm from the bottom

Answer

D

Explanation

`1/(4piepsilon_0)q^2/r^2=mg sintheta`
`r=sqrt((1/(4piepsilon_0))(q^2/(mgsintheta)))`
`sqrt(((9xx10^9)(2.0xx10^-6)^2)/((0.1)(9.8)sin30^@))`
`=27xx10^-2m`
`=27cm