Electromegnetic induction unerstanding changing flux

[patelpalak]

Homework Statement

In this problem, you will use Lenz's law to explore what happens when an electromagnet is activated a short distance from a wire loop.
You will need to use the right-hand rule to find the direction of the induced current.


Finally, the switch on the electromagnet is reopened. The magnitude of the external magnetic flux through the wire loop ______ (A. increases, B. decreases, C. remains constant), and there is _______ (A. zero, B. a clockwise, C. a counterclockwise) current induced in the loop (as seen from the left).

 

[LowlyPion]

Welcome to PF.

What are your thoughts on how to solve it?

 

[nlightner]

I can explain that electromagnetic induction is the process of creating an electric current in a conductor by varying the magnetic field around it. This phenomenon is governed by Faraday's law and Lenz's law, which state that the induced current will flow in a direction that opposes the change in magnetic flux.

In this specific scenario, when the switch on the electromagnet is closed, it creates a magnetic field that passes through the wire loop. This changing magnetic flux induces an electric current in the loop, which can be determined using the right-hand rule. The direction of the induced current will depend on the direction of the magnetic field and the motion of the wire loop.

When the switch is reopened, the magnetic field from the electromagnet will decrease or collapse. This change in magnetic flux will again induce an electric current in the wire loop, but in the opposite direction as before. This is because the induced current will always flow in a direction that opposes the change in magnetic flux, as per Lenz's law.

Lastly, the magnitude of the external magnetic flux through the wire loop will decrease when the switch is reopened, therefore the correct answer to the first question is B. decreases. And since the induced current will flow in the opposite direction as before, the correct answer to the second question is C. a counterclockwise current.