1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: B field inside solenoid as a result of iron rod

  1. May 12, 2013 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    Consider a solenoid with a time varying current and with a coil of wire placed around it. Suppose there is a soft iron rod inside the solenoid. My question is: What happens to the (induced) current in the coil of wire as a result?

    2. Relevant equations
    Faraday, magnetic flux,

    3. The attempt at a solution

    Since iron is ferromagnetic, (it has associated with it a permanent magnetic dipole moment), it gives out a net B field. So the B field inside the solenoid is increased. Since $$\phi_B = BA,$$ the magnetic flux then increases and hence the induced emf in the wire by Faraday. This causes the induced current to increase also.

    Is this okay?

    Many thanks.
  2. jcsd
  3. May 12, 2013 #2
    Looks good.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted