Register to reply

Magnet in a AC current solenoid

by sgstudent
Tags: current, magnet, solenoid
Share this thread:
Feb10-12, 09:49 PM
P: 645
when you place a magnet into a solenoid with a ac current it will get demagnetised. So does this mean that the magnetic field will go into the magnet in the opposite direction of the magnet's own magnetic field? and disalign it. meaning will the magnetic field enter the magnet as though it is like another piece of iron?

thanks for the help!
Phys.Org News Partner Physics news on
'Squid skin' metamaterials project yields vivid color display
Team finds elusive quantum transformations near absolute zero
Scientists control surface tension to manipulate liquid metals (w/ Video)
Mar17-12, 02:32 AM
P: 3
A rapidly alternating mag field will dis-arrage the mag-wessels. hence deenergising the same.
Mar17-12, 04:34 AM
P: 409
Perhaps it's easier to consider the magnet as a large number of atoms. Since electron and protons have very small dimensions, most of the atom is empty space ( vacuum). So, the magnetic field "enters" the magnet. The filed there applies toque on electron magnetic dipoles.The torque doesn't simply rotate the dipole to get parallel with the field but it initially cause precession. the precession damps usually after a short time ( in order of nano-seconds) and the new alignment would be parallel with the applied field ( assumed strong enough to case the reversal)

jim hardy
Mar17-12, 07:27 AM
Sci Advisor
PF Gold
jim hardy's Avatar
P: 3,739
Magnet in a AC current solenoid

This link,

on page 27 & 28 (PDF pages 29 & 30) speaks to demagnetizing of transformer cores that have retained magnetism.

They have a different shaped B-H curve than your permanent magnet but principle is same.

If thet link doesn't work, search on : ittechinfoappguide.pdf

and pick this one:

Register to reply

Related Discussions
Solenoid and A Magnet Classical Physics 3
Force of a solenoid on a magnet? General Physics 1
EMI - Current in solenoid due to magnet Introductory Physics Homework 1
Would running an electrical current through a magnet destroy the magnet? General Physics 4
Magnet rod for Solenoid Electrical Engineering 1