Question

Two charges $q$ and $-2q$ are separated by a distance $d$. If the electric intensity at the site of $q$ is $E$ then the electric field intensity at the site of $-2q$ is:

• A. $E$
• B. $E/2$
• C. $-2E$
• D. $-E/2$

Answer 1

The correct option is D $-E/2$

As the force between two charges $F$ is mutual.
Electric intensity at the site of $q$ is $E=\frac{F}{q}$
Electric intensity at the site of $-2q$ is $E^1=\frac{F}{-2q}=-\frac{E}{2}$