Question

Two connected charges of $+q$ and $-q$ respectively are at a fixed distance $AB$ apart in a non uniform electric field whose lines of force are shown in the figure. The resultant effect on the two charges is

• A. a torque in the plane of the paper and no resultant force
• B. a resultant force in the plane of the paper and no torque
• C. a torque normal to the plane of the paper and no resultant force
• D. a torque normal to the plane of the paper and a resultant force in the plane of the paper

Answer 1

The correct option is D a torque normal to the plane of the paper and a resultant force in the plane of the paper

As refer to IMAGE 01:The electric field line show that there is negative charge present nearby the positive charge.

Now, ${\overrightarrow{F}}_1>{\overrightarrow{F}}_2$ because of non-uniform electric field.

$\therefore$ there will be a force in the plane of paper.

Next there will be a torque to align the charge. i.e. to move $+ve$ charge downwards and $-ve$ charge upward which will result of a torque normal to the plane of the surface.