Question

A conducting loop is held above a proton carrying wire $\text{AB}$ as shown in the figure. What is the direction of the induced electric field in the loop when the proton in the wire $\text{AB}$, is constantly increasing.

• A. clockwise direction
• B. anti-clockwise direction
• C. into the plane of paper
• D. out from the plane of paper

Answer 1

The correct option is B anti-clockwise direction

We are given that the direction of the proton is from right to left. Clearly, current will flow from right to left as current flows in the same direction as that of proton (positive charge).

The magnetic field established due to this current flow in the coil is into the plane of paper.

Now, using Lenz’s law, the direction of induced current in the coils needs to be in such a way that the induced magnetic field in the coil is out of the plane of paper.

Using right-hand thumb rule, the direction of induced current in the coil will be in the anti-clockwise direction.


We know that the direction of the induced electric field is the same as the direction of induced current in a circuit.

Therefore, the electric field will also induce in the anticlockwise direction.

Hence, $\left(\text{B}\right)$ is the correct answer.