Faraday's Law

  • Thread starter gadje
  • Start date
  • #1
23
0

Homework Statement


A square of side 2cm, in the first quadrant of the x-y plane, with a corner at the origin, is in a magnetic field pointing out of the page of magnitude 4t2y.

Calculate the emf around the square at t = 2.5s and give its direction.


Homework Equations



[tex] \epsilon = - \frac{d}{dt} \Phi [/tex]


The Attempt at a Solution



Do I do it like this?

[tex] \epsilon = -\frac{d}{dt} \int ^2 _0 \int ^2 _0 4t^2 y \ dx \ dy [/tex]

If so, then great. If not, what do I do?
 

Answers and Replies

  • #2
77
0
Yeah, that seems correct as you are just using the definition of flux:
[tex]\phi = \int \vec{B} \cdot \vec{dA} [/tex]

And subbing that into your above expression for the emf.

It looks correct but I'm not certain as I'm only a mere first year so you should probably get someone else to confirm.
 
  • #3
699
6
It looks correct, but I would double check the units of distance, magnetic field and voltage. What system of units are you using for Maxwell's equations? I normally use SI units with meters, Telsa and Volts, so I would have set my upper limits at 0.02 rather than 2. However, if you are using CGS units it may be correct - just double check it.
 
  • #4
23
0
Yeah, I screwed up the units in the OP; had them right in my paper calculation.
 
  • #5
699
6
Yeah, I screwed up the units in the OP; had them right in my paper calculation.
OK, good! I guess you're using SI units. I think with cgs (or, more accurately Gaussian) units there might be a speed of light factor involved.
 
Last edited:

Related Threads on Faraday's Law

  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
5
Views
806
  • Last Post
Replies
5
Views
5K
  • Last Post
Replies
3
Views
930
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
5
Views
1K
Top