Charge and Electric Force Practice Test

e = 1.60 times $10^{-19}$

k = 8.99 times $10^{9}$

How many electrons would it require to generate a 5 N attractive force on a +3 µC charge from 0.1 m away.

Two charges Q1 and Q2 are held stationary 1 m away from each other. The magnitude of charge of Q2 is twice that of Q1. A positive point charge A is placed directly in the middle of the two charges (Q1 and Q2). What is the ratio of the net force on charge A when Q1 and Q2 are both negative over the net force on charge A when Q1 is negative and Q2 is positive?