A negative charge `q_(1)=50 xx 10^(-9)C` and a positive charge `q_(2)=25 xx 10^(-9)C` are fixed at a distance l=20cm. Where should a thrid charge q be placed on the line joining the charges so that they may be in equillibrium? What is the nature of equillibrium with respect to its longitudenal displacement along the line joiing the two charges? Plot a grapgh showing dependence of this force on distance from `q_(@)`.
