Question 17 Three point charges q, 2q and 8q are to be placed on a 9 cm long straight line. Find the positions where the charges should be placed such that the the potential energy of this system is minimum. In this situation, what is the electric field at the charge q due to the other two charges?
Solution : The maximum contribution may come from the charge 8q forming pairs with others. To reduce its effect, it should be placed at a corner and the smallest charge q in the middle.