What is the induced current in a resistor due to a moving wire with current?

  • Thread starter Thread starter IndyKuma
  • Start date Start date
  • Tags Tags
    Electromagnetic
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 1K views
IndyKuma
Messages
1
Reaction score
0

Homework Statement


A rectangle circuit which has a resistor R and has a size l*w. The circuit is moving away from an infinite long wire which has a current i moving up along the wire with velocity v. Find the current moving in the resistor's side which far from the wire r. Here's the figure of the problem. http://imgur.com/RcAbgVN

Homework Equations


Maybe Faraday's Law? Like, Φ = ∫ B ⋅ dA and ε = -dλ/dt .

The Attempt at a Solution


I found that my answer is -μ0ilv/2πr. But I'm not sure about it.
 
Last edited:
Physics news on Phys.org
I get a different answer, involving all the given parameters.
When dealing with moving media such as this loop, use the Blv law rather than Faraday's law. The latter can lead to difficulties.
The Blv law simply states that the voltage induced across a wire (for example) of length l moving at speed v and at right angles to a B field is emf = Blv. In vector form, emf = B⋅ (l x v).

In this case you have two lengths inducing differing emf's. Hint: what happens if you connect two batteries of differing voltages + to + (or - to -)?