Two point charge +q and -q are separated by a distance d. Where besides at infinity is the electric potential zero?

Two point charges 4Q and Q are separated by a distance of 1 m in air. Also calculate the electrostatic potential energy of the system of two charges, taking Q = 2 xx 10^-7C .

Two points charges +10muC and -10muC are separated by a distance of 40 cm in air. Calculate the electrostatic potential energy of the system, assuming the zero of the potential energy to be at infinity.

Two fixed point charge 4Q and 2Q are separated by a distance x. where should a third point charge q be placed for ti to be in equilibrium?

Two charges -q each are separated by distance 2d. A third charge +q is kept at mid-point O. Find the potential energy of +q as a function of small distance x from O due to -q charges. Sketch P.E. v/s x and convince yourself that the charge at O is an unstable equilibrium?

Two point charges 4Q and Q are separated by a distance of 1 m in air. At what point on the line joining the two charges is the electric field intensity zero?

Two point charges 4 mu C and -2 muC are separated by a distance of 1 m in air. At what point on the line joining the charge is electric potential zero?

Two point charges of +5xx10^-19C and +20 xx 10^-19 C are separated by a distance 2m. Find the point on the line joining them at which electric field intensity is zero.

Two point charges q_1 and q_2 are kept at a distance of r_(12) in air. Deduce the expression for the electrostatic potential energy of the system.