Question

A charge $q_1$ exerts some force on a second charge $q_2$. If a third charge $q_3$ is brought near, the force of $q_1$ exerted on $q_2$:

• A. decreases
• B. increases
• C. remains unchanged
• D. increases if $q_3$ is of same sing as $q_1$ and decreases if $q_3$ is of opposite sign.

Answer 1

The correct option is C remains unchanged

According to the principle of superposition,
The force between any two charged particles is independent of all other charges in the universe.

The force of $q_1$ or $q_2$ is not affected by $q_3$.
Note that, however, resultant force on $q_2$ will be affected.