Question

Two point charges $q$ and $5q$ are placed in vicinity of each other. Charge $q$ applies force $\overrightarrow{F}$ on charge $5q$, then force by charge $5q$ on charge $q$ is

• A. $5\overrightarrow{F}$
• B. $-5\overrightarrow{F}$
• C. $-\overrightarrow{F}$
• D. $-\frac{\overrightarrow{F}}{5}$

Answer 1

The correct option is C $-\overrightarrow{F}$

According to Newton's third law:
Force between $q$ and $5q$ must be equal and opposite in nature, as they form action-reaction pair.
$\therefore$ Force by charge $5q$ on charge $q$ is $-\overrightarrow{F}$