Two insulating small spheres are rubbed against each other and placed 1cm apart.If they attract each other with a force of 0.1 N how many electrons weretransfered from 1 sphere to the otherduring rubbing

F= 0.1 N = 9 * 10⁹ * q²/r²

q²= 0.1 * 0.01²/(9 * 10⁹)

q²= 10/9 * 10^-15

no of electrons transferred = q/1.6 * 10^-19= 3.34* 10^-8/1.6 * 10^-19

                                                             =2 *10^{11 (Approx.)}

q2= 0.1 * 0.012/(9 * 109)

q2= 10/9 * 10-15

no of electrons transferred = q/1.6 * 10-19= 3.34* 10-8/1.6 * 10-19

                                                             =2 *1011 (Approx.)

Helps !