Chapter 21, Problem 4P

If the solenoid in Fig. 21-59 |D is being pulled away from the loop shown, in what direction is the induced current in the loop? Explain.

To determine

Answer to Problem 4P

Direction of induced EMF in the loop when solenoid is being pulled out of it.

Solution:

Explanation of Solution

Direction of current in the loop will be counter clockwise.

Current flows in counter clockwise direction in solenoid when viewed from right thus the solenoid produces a magnetic field directed towards the right. if the solenoid is pulled away from the loop then the right wards flux through the loop becomes weaker to counteract this change through the loop according to Lenz's law an EMF and resulting current will be induced in such a way that the magnetic field produced by induced current must point to the right, opposing the loss in right wards magnetic flux to the loop. this implies that the induced current must be following around the loop counterclockwise sense when viewed from the right.

Conclusion:

Applying Lenz's law, we get the direction of induced current in the solenoid as counterclockwise