Can a permanent magnet be turned off and on?

Answer 1

Electromagnet.

it is a piece of metal (usually iron) that is wrapped in copper wire.

it is turned on by putting electricity through the copper wire. it then producces a magnetic field when electricity is run through it.

Answer 2

No, a bar magnet cannot really be "turned off" in the manner of a light switch. The magnetic domains are set up when the magnet is manufactured, and there they pretty much stay. But there is a thing called the Curie point we need to review.

If a permanent magnet is heated beyond the Curie point for the material of which it is made, the magnetic domains, which were sort of "locked in place" when the magnetic was made, get "scrambled" because the material is so hot. The heating of the material of the magnet allows the atoms it is made of to move around considerably, and these atoms will abandon the structure that has uniformly arranged their magnetic domains. The magnet loses its magnetic ability, and when it cools below the Curie point, the field will not reestablish itself. In this case, the magnet is "turned off" in a permanent way.

A bar magnet can have its field reduced by wrapping a coil of wire around it and applying a current through the coil. With enough current through the coil the magnetic strength at the ends of the magnet can be reduced or increased temporarily as long as the current is applied. If the coil is energized with high enough current the magnet may be heated above its Curie point and the magnet will loose its initial strength.

Answer 3

Not in the same way an electromagnet can be turned on and off. As the name suggests the magnetism is permanent. However there are ways a permanent magnet can be de-magnetised but it is not a simple on/off procedure.

Answer 4

An electro magnet can, but not the other kind.

Answer 5

That is called an electromagnet. When the current flows, there is magnetism, when the current is switched off, the magnet stops working as a magnet.

Answer 6

Yes, if you open the electrical circuit of an electromagnet there will no longer be any magnetism.

Answer 7

True