Induced current in magnet (what would happen if....)

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Homework Help Overview

The discussion revolves around the concept of induced currents and magnetic fields, specifically in the context of a magnet's motion relative to coils. The original poster expresses confusion regarding the behavior of induced currents and their relationship to the direction and speed of the magnet's movement.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • The original poster attempts to describe their understanding of induced currents and magnetic fields, posing questions about the effects of reversing the magnet's motion and increasing its speed. Participants question the clarity of the original poster's descriptions and seek to clarify the direction of current flow.

Discussion Status

The discussion is ongoing, with participants providing insights and seeking clarification on various points. Some guidance has been offered regarding the direction of current flow, but there remains uncertainty about the implications of changing the magnet's speed and direction.

Contextual Notes

The original poster notes that they have not yet learned about Faraday's law, which may limit their understanding of the concepts being discussed.

A-linav

Homework Statement


Screen Shot 2017-08-12 at 10.54.54 PM.png


Homework Equations


N/A

The Attempt at a Solution


[/B]
I'm having a lot of trouble understanding induced magnetic fields. I was wondering if someone can explain it for me and confirm if I have the right answers?

a) I labelled it [North | South], and the direction of the current is going counterclockwise
b) If the direction of motion of the magnet is reversed, the direction of the current is reversed (in this case it would go clockwise and [South | North] ). The magnetic field produced by the current will oppose the change that produces the current and pull back on the bar magnet, resisting the inducing action.
c) If the magnet is moved more quickly, the coils will rotate faster and a greater current will be created. (Im not sure what would happen to the magnetic field? would it be a stronger opposing force?)
d) I am completely lost at this last question... Would the induced current be greater because there is a constant change in direction/speed? Would the magnetic field be greater because it is constantly changing?

This is just an introductory course so I have not learned about Farraday's law (only Lenz's law). Any insight is appreciated please and thanks!
 

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A-linav said:
[North | South], and the direction of the current is going counterclockwise
Not quite sure what you mean by counterclockwise in this context.
Are you saying it would be left to right in the straight portion and right to left (as viewed in the diagram) in the coil?
That doesn't sound right to me.
 
haruspex said:
Not quite sure what you mean by counterclockwise in this context.
Are you saying it would be left to right in the straight portion and right to left (as viewed in the diagram) in the coil?
That doesn't sound right to me.

I meant it like this picture right here how it's coiled. Am I right?
And am I right about the other questions?
 

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A-linav said:
the coils will rotate faster
The coils don't move.
A-linav said:
would it be a stronger opposing force?)
Yes.
A-linav said:
Im completely lost at this last question
I'm not sure what they after either. Maybe something about resonance?
A-linav said:
I meant it like this picture right here how it's coiled. Am I right?
Ok. The problem with just saying "counterclockwise", meaning the direction the current flows around the rod, is that it depends which end of the rod you are looking from.
 

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