Question

two point charge 1 mC and -1 mC and 9 m apart . potential at the centre of the line joining the two charges is​

Answer 1

Answer:

Electric potential at a point is defined as the work done in bringing a unit positive test charge from infinity to that point. Now take the perpendicular bisector from the center of the line joining the charges to infinity. If you bring a positive test charge from infinity along that line it will be equally repelled and attracted by the equal and opposite 1mC charges and the work done in bringing  the test charge along that line will be zero so the required potential is zero.