As shown in the adjoining figure two charge particles each having charge `q` and mass `m` and `d` distance apart from each other. If two particle in equilibrium under the gravitational and electric force, then determine the ratio `q//m`.

Options

A. `10^(-8)`
B. `10^(-10)`
C. `10^(10)`
D. none

Explanation

(b) Condition for equilibrium `F_(e)=F_(q)`
`(kq^(2))/(d^(2))=(Gm^(2))/(d^(2))`
`implies1/(4piepsilon_(0))(q^(2))/(d^(2))=(Gm^(2))/(d^(2))`
or `(q^(2))/(m^(2))=G(4piepsilon_(0))`
`q/m=sqrt((Gxx4piepsilon_(0)))/1`
`=sqrt((6.67xx10^(-17))/(9xx10^(9)))=10^(-10)`