Finding direction of induced current

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SUMMARY

The discussion centers on determining the direction of the induced current in a wire loop when it is dragged across the south pole of a magnet. The correct answer is that the current will flow counter-clockwise when viewed from above, as per the right-hand rule. This is due to the principle that the induced current creates a magnetic field opposing the change in magnetic flux through the loop. The confusion arises from the interpretation of the loop's movement relative to the magnet's position.

PREREQUISITES
  • Understanding of electromagnetic induction principles
  • Familiarity with the right-hand rule for current direction
  • Basic knowledge of magnetic fields and their orientation
  • Concept of magnetic flux and its changes
NEXT STEPS
  • Study Faraday's Law of Electromagnetic Induction
  • Learn about Lenz's Law and its application in induced currents
  • Explore the right-hand rule in different contexts of electromagnetism
  • Investigate the effects of varying magnetic fields on induced currents
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Students of physics, educators teaching electromagnetism, and anyone interested in understanding the principles of induced currents and magnetic fields.

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Homework Statement


The right side of a wire loop is dragged to the left across the south pole of a magnet. What will be the direction of the current induced in the loop?

a. No current will flow around loop.
b. Current will move in the wires of the loop in the same direction as the loop itself.
c. Current will move in the wires of the loop in the opposite direction as the loop itself.
d. Current will oscillate back and forth around the loop (AC current)
e. Current will flow clockwise around the loop.
f. Current will flow counter-clockwise around the loop.


2. The attempt at a solution
Because of the right hand rule, would the current be moving counterclockwise (f)?

Also does the magnetic field point to the right?

What difference does it make when the right side is dragged vs the left side?

Also, why does a down direction of t he current cause a clockwise current throughout the loop as opposed to a counterclockwise current?
How do you know if the current will move in the wires or around the loop? Can I eliminate b and c because an induced current involves moving a loop over a magnet?
Please help, I'm very confused!
 
Last edited:
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The answers depend on what is meant by "right side" etc.
These descriptions seem to be specific to your course.

The rule you want is that the current will flow so as to set up a magnetic field that opposes the motion of the magnet.

Moving the loop one way is the same as moving the magnet the other way.

So - if you have a loop in the x-y plane, centered at the origin, so is follows x^2+y^2=r^2 and r is the radius of the loop...

Looking down the +z axis at the loop, a magnet placed in position z>0 will be "above" and if it moves from -x values to +x values, then it moves from left to right.

If it goes south-pole downwards, then the magnetic field is pointing "upwards".
As the magnet crosses into the loop, the field inside the loop gets "more south".
What pole is needed to oppose that motion?
 

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