Electromagnetic induction problem

Click For Summary
SUMMARY

The discussion centers on calculating the current flowing through circuit ABCD when the center of the circuit (O) is at a distance r from a straight wire. Key equations mentioned include the magnetic field B given by B = μ₀I/2πr, the electromotive force E = -d∅/dt, and the flux ∅ = B.dS. The user struggles with the differential area element dS and its relation to time, specifically how to express it in terms of velocity v and eliminate dt. Clarifications indicate that while the area S remains constant, the magnetic field B changes over time.

PREREQUISITES
  • Understanding of electromagnetic induction principles
  • Familiarity with the Biot-Savart Law
  • Knowledge of calculus, particularly differentiation and integration
  • Basic concepts of electric circuits and current flow
NEXT STEPS
  • Study the Biot-Savart Law for calculating magnetic fields
  • Learn about Faraday's Law of Electromagnetic Induction
  • Explore the relationship between magnetic flux and induced electromotive force
  • Investigate the concept of time-varying magnetic fields in circuits
USEFUL FOR

Students in physics, electrical engineering majors, and anyone studying electromagnetic theory or circuit analysis will benefit from this discussion.

oportunity
Messages
9
Reaction score
0

Homework Statement



http://imageshack.us/photo/my-images/194/55132039.png/

http://imageshack.us/photo/my-images/194/55132039.png/

How much curret flows trough circuit ABCD when the center of the circuit (O) is distance r from the straight wire? I think these are the relevant equations:
∅=B.dS
E=-d∅ /dt
B= μoI/2∏r

But i have trouble with dS. i know that is has to be rewritten like e.g. ds= ydx=yvdt and that way eliminate dt
but in this case i don't know how to do it.

Thanks
 
Physics news on Phys.org
Well, obviously v is associated with dψ/dt where ψ = ∫BdS (apperently you are using S for area.) (Sorry, the symbol table does not have a Greek letter for "phi", can't imagine how that fell thru the cracks).

You have the right formula for B(r), you know v = dr/dt, right? So how does ∫BdS change with time? S doesn't change with time, it's just the area of the square ... so it must be B that is changing ...
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 16 ·
Replies
16
Views
5K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K