2. A 1C charge is placed at the origin. Other infinite numbers of unit charges are placed at √2, √4, √8, √16,….(up to infinite) distances from the origin in a straight line. What will be the total force acting on the 1st charge? a) 9*109 N b) 18*109 N c) Infinite d) 1 N
Answer: a Explanation: The force on 1st charge will be = 9*10-9*(12√2+14√2+18√2 +⋯) = 9*10-9*121−12 = 9*10-9N [infinite GP formula].
