Question

Two identical point charge Q are kept at a distance r from each other. A third point charge -q is placed on the line joining the above two charges such that all the three charges are in equilibrium. What is the magnitude, sign and the position of the third charge ?

Answer 1

Answer:

Two identical point charge Q are kept at a distance from each other. A third point charge -q is placed on the line joining the above two charges such that all the three charges are in equilibrium. what is the magnitude, sign and the position of the third charge? Thank for your information.

Answer 2

Answer:

using KQq/r²,

for the equilibrium of q ,

KQq/x²= KQq/(r-x)²

so, x = r/2

for the equilibrium of Q ,

KQq4/r²= -KQ²/r²

so, q is -Q/4