Will Changing Loop Size Affect Induced Current? | Magnetic Field Question

  • Context: Undergrad 
  • Thread starter Thread starter jtrexler
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the effects of various actions on a conducting loop placed in a magnetic field, specifically focusing on whether these actions will induce a current in the loop. The scope includes conceptual understanding of electromagnetic induction and the relationship between loop size and induced current.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that changing the size of the loop affects the magnetic flux, which could induce a current.
  • Others argue that relative motion is not the only factor that induces current; the nature of the motion and its effect on magnetic flux is also crucial.
  • One participant notes that increasing or decreasing the strength of the magnetic field will induce current, eliminating those options from consideration.
  • There is uncertainty about whether changing the area of the loop constitutes relative motion in the context of inducing current.
  • A participant suggests that rotating the loop about an axis parallel to the field will not induce current, as it does not change the magnetic flux.

Areas of Agreement / Disagreement

Participants express differing views on whether changing the size of the loop constitutes relative motion that induces current. There is no consensus on the implications of loop size changes or the specific actions that will or will not induce current.

Contextual Notes

Participants discuss the concept of magnetic flux and its relationship to induced current without resolving the nuances of how different actions impact this relationship. The discussion reflects varying interpretations of the principles of electromagnetic induction.

jtrexler
Messages
2
Reaction score
0
A conducting loop of wire is placed in a magnetic field that is normal to the plane of the loop. Which one of the following actions will not result in an induced current in the loop?

1)Decrease the area of the loop.

2)Increase the strength of the magnetic field.

3)Decrease the strength of the magnetic field.

4)Rotate the loop about an axis that is parallel to the field and passes through the center of the loop.

5)Rotate the loop about an axis that is perpendicular to the field and passes through the center of the loop.
-------------------------------------------

Now, I know the basics of magnetic fields- as long as there is relative motion between a magnet and a loop there will be current in the loop. But I am having issues with this question. Is changing the size of a loop "relative motion"?
Thanks for your help.
 
Physics news on Phys.org
Originally posted by jtrexler
A conducting loop of wire is placed in a magnetic field that is normal to the plane of the loop. Which one of the following actions will not result in an induced current in the loop?

1)Decrease the area of the loop.

2)Increase the strength of the magnetic field.

3)Decrease the strength of the magnetic field.

4)Rotate the loop about an axis that is parallel to the field and passes through the center of the loop.

5)Rotate the loop about an axis that is perpendicular to the field and passes through the center of the loop.
-------------------------------------------

Now, I know the basics of magnetic fields- as long as there is relative motion between a magnet and a loop there will be current in the loop. But I am having issues with this question. Is changing the size of a loop "relative motion"?
Thanks for your help.


Increasing or decreasing the strength of the magnetic field will cause the magnetic field to interact with the loop, causing induction, so, 2 & 3 are out.
5 obviously causes induction so 5 is out.
This leaves 1 & 4.
Not sure where to go from there.
 
Originally posted by jtrexler

Now, I know the basics of magnetic fields- as long as there is relative motion between a magnet and a loop there will be current in the loop. But I am having issues with this question. Is changing the size of a loop "relative motion"?
Yes. Changing the size of the loop changes the magnetic flux and induces a current.

Careful with the idea that relative motion always induces a current in the loop. If the relative motion does not impact the flux (as in #4) there will be no induced current in the loop.
 
Okay, thanks for the help. I thought that changing the area of the loop would induce a small amount of current, but wasn't sure if that was what the question was going for.
 

Similar threads

Undergrad DC current flows in a wire when two loops are brought close by?
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad The vector math of relative motion of wire-loop & bar magnet
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Questions about cancelation of induced EMF and minimizing eddy currents
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Charge movement relative to magnetic field frame dependence/invariance
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Faraday induction in constant B field, with non-conduction wires
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Work Done in Changing Shape of Current Carrying Loop
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Derivation of induced voltage in loop
  • · Replies 32 ·
2
Replies
32
Views
3K
Undergrad Maximum Induced Voltage of an AC Generator
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad How induction works within a coil (nuances of it)
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Magnetic field on a loop due to another loop
  • · Replies 2 ·
Replies
2
Views
16K