Given are four arrangements of three fixed electric charges. In each arrangement, a point labelled `P` is also identified- test charge, `+q`, is placed at point `P`. All of the charges are of same magnitude `Q`, but they can be either positive of negative as indicated. The charges and point `P` all lie on a straight line. The distances between adjacent items, either between two charges or between a charge and point `P`, all are the same.

Given are four arrangements of three fixed electric charges. In each arrangement, a point labeled P is also identified. A test charge +q is placed at P. All of the charges are of the same magnitude Q, but they can be either positive or negative as indicated. The charged and point P all lie on a straight line. the distances between adjacent items, either between two charges or between a charge and point P, are all the same. I. o+,o+,o+,underset (P)(*) , II. o+,o+,overset(P)(*),- III. o+,o+,-, overset(P)(*) , IV. o+, - , o+, overset(P)(*) . Correct order of choices in a decreasing order of magnitude of force on P is

The charges q each are placed at a distance 2a and a third charge -2q is placed at the mid point. The P.E. of the system is

A point charge Q is placed at point O. potential difference V_(A)-V_(B) is positive. Is the charge Q negative or positive ?

A charge +q is placed at the mid point between two unit negative charges. What should be the magnitude of the charge q so that the three charges remain in equilibrium state?

A positive charge q_(0) placed at a point P near a charged of metal sphere experience a force of repulsion of magnaitude F , the electric field E of the charge metal, charge at P is

Consider the points lying on a straight line joining two fixed opposite charges. Between the charges there is

Two unit negative charges placed on a straight line. A positive charge q is placed exactly at the mid point between these unit charges. If the system of these three charges is in equilibrium, the value of q (in C) is