1
$\begingroup$

Permanent magnets seems to have different properties to electromagnets, such that electromagnets can be used for induction and energy transfer if a conductor is placed within their changing magnetic field.

So I understand that an electromagnet will have a changing magnetic field, which in turn generates a changing electrical current in a conductor placed within this magnetic field.

My question is, do permamant magnets generate this same electric current if a conductor is placed within their magnetic field?

I.e. if I had a strong permanent magnet, would I be able to generate a current in a coil if it was brought into the permananet magnet's magnetic field?

$\endgroup$
1
$\begingroup$

To answer your question in one word, "Yes"

Now, onto the explanation:-

According to Faraday's Law, you will get a current in a conductor when the amount of magnetic flux linked with the conductor changes.

Note that it is immaterial whether the source of the magnetic field is a permanent magnet or an electromagnet. All that needs to happen for you to detect a current in the conductor is for the flux to change.

In case of the electromagnet, when you change the strength of the field; the flux linked with the coil changes and current is induced.

In case of the permanent magnet, your field is fixed; you can't change it. But, if there is relative motion between the permanent magnet and the coil; then the flux linked with the coil will change and if that happens,current will definitely be induced.

$\endgroup$
3
$\begingroup$

According to Faraday's law of induction, $$\mathcal{E} = -N {{d\Phi} \over dt}$$ you will need a change in the magnetic flux $\Phi$ in order to get an EMF or an electric field.

So if you just put your coil in the magnetic field of the permanent magnet, you will not measure a current. There will only be a current, if you move the coil around so that the flux changes.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.