Finding direction of induced current

  • Thread starter 16Candles
  • Start date
  • #1
6
0

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:

Answers and Replies

  • #2
Simon Bridge
Science Advisor
Homework Helper
17,857
1,655
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?
 

Related Threads on Finding direction of induced current

Replies
1
Views
2K
  • Last Post
Replies
4
Views
5K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
12
Views
734
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
17
Views
6K
Replies
0
Views
2K
Replies
10
Views
3K
Replies
1
Views
1K
Top