Could Someone Help Me With This Lenz's Law Question?

  • #1
The bar in figure Q31.5 moves on rails to the right with a velocity, v, and the uniform, constant magnetic field is directed out of the page. Why is the induced current clockwise? If the bar were moving to the left, what would be the direction of the induced current?
(The figure is at the bottom of page 24 in the document linked below)

My answer is;
As Lenz's law states that the induced current in a conductor acts in the direction that opposes the charge that produced it. Consequently, the magnetic field is acting into the page, meaning that the induced current is clockwise (by the right hand rule).
If the bar was moving to the left, the induced current would be counter-clockwise.

If this correct?

Thank you for any help =)

http://www.electron.rmutphysics.com...-Serway-Beichne 6edr-4/31 - Faraday's Law.pdf
 

Answers and Replies

  • #2
Spinnor
Gold Member
2,159
361
For a moving conductor in a magnetic field can't you just use that the force on a charge q is F = q*VXB and this force causes a current?
 
  • #3
vela
Staff Emeritus
Science Advisor
Homework Helper
Education Advisor
14,793
1,379
My answer is;
As Lenz's law states that the induced current in a conductor acts in the direction that opposes the charge that produced it. Consequently, the magnetic field is acting into the page, meaning that the induced current is clockwise (by the right hand rule).
If the bar was moving to the left, the induced current would be counter-clockwise.

If this correct?
The picture didn't load here when I clicked on the link, but I can imagine what it was.

You kind of just assert what the answer is. Can you explain in a bit more detail how you know the induced field points into the page?
 

Related Threads on Could Someone Help Me With This Lenz's Law Question?

Replies
1
Views
4K
Replies
7
Views
892
  • Last Post
Replies
12
Views
5K
  • Last Post
Replies
8
Views
1K
Replies
1
Views
873
  • Last Post
Replies
5
Views
2K
Replies
3
Views
1K
  • Last Post
Replies
5
Views
1K
Replies
1
Views
2K
Replies
1
Views
1K
Top