Two negative point charges each of magnitude 2 esu and another point charge q are lying on a straight line. Each of the charges are in equilibrium. Determine the position, value and the nature of the charge q.

Two negative point charges each of magnitude 8xx10^(-8)C and another positive charge Q are placed on the same straight line. At what position and for what value of Q, the system will remain in equilibrium?

Two negative charges each of 1 unit and a positive charge q are placed on a straight line. Where should the charge q be placed and what should be its value for equilibrium of the charges? Is this equilibrium stable, unstable or neutral ?

Two point charges Q and q are placed at distance r and r/2 respectively alogn a straigt line from a third charge 4q. If q is in equilibrium determine Q/q .

Two negative charges of a unit magnitude and a positive charge q are placed along a straight line. At what position and value of q will the system be in equilibrium? (Negative charges are fixed).

Two negative charges of a unit magnitude and a positive charge q are placed along a straight line. At what position and value of q will the system be in equilibrium? (Negative charges are fixed).

Two positive point charges Q and one negative point charge q are arranged in a straight line in such a manner that the complete system remains in equilibrium. What can be the magnituude of Q/q ?

Two point charges +q and -q are placed a distance x apart. A third charge is so placed that at the three charges are in equilibrium. Then

(a) Derive and expression for the electric field at any point on the equatorial line of an electric dipole. (b) Two identical point charges, q each kept 2m apart in air. A third point charge Q of unknown magnitude and sign is placed on the line joining the charges such that the system remains in equilibrium. Find the position and nature of Q.

Two point charges each of magnitude +q are placed at a distance r from each other. Draw the lines of force in this case.