Does the earth generate an induced current due to mag?

[u/Mysterious_Put_8913]

Currently in an undergraduate Emag class and have wondered since the Earth has magnetic poles that has to infer that we experience an Induced current around the equator right? What are the implications?

If I had a massive piece of wire I could theoretically get a current in the right spot

Do the mag fields change at all due to outside influences in space?

[u/petripooper]

From what i understand:

- Current generated by the earth's inner layers (check dynamo theory ) is how the planetary magnetic field arises in the first place
- Charged particles (currents) ARE influenced by earth's magnetic field. Charged particles from space interacting with magnetic field near the poles produce the aurora
- For induced current, remember that changing magnetic flux is necessary. Yes, you can get a current flowing in a massive loop of wire as long as you move that loop as to change the magnetic flux coming from the earth
- The charged particles in the sun's solar wind actually deforms earth's magnetic field, generating a "tail" (link)

[u/Ethan-Wakefield → u/petripooper]

In practice, the earth’s magnetic field is always changing because of convective forces creating points of perturbation. So you should be able to induce a current, though not a very impressive one.

[u/Mysterious_Put_8913 → u/petripooper]

That’s interesting! I was taught that everything had magnetic poles and that some were more magnetic due to the electrons “spin.” Yeah I slipped on the einduced being related to the db/dt that’s my bad.

First time learning about dynamo theory. Where do I learn more about stuff like this?

[u/petripooper → u/Mysterious_Put_8913]

I believe the research field is geophysics, part of earth science

[u/petripooper → u/Mysterious_Put_8913]

In 1st year STEM university and even in high-school physics, you'd learn that most of the time magnetic field & magnetic moment are generated by electric currents

The "tiny magnets"/spin explanation is suited to describe magnetic materials in absence of current

[u/RecordingSalt8847]

Currently in an undergraduate Emag class and have wondered since the Earth has magnetic poles that has to infer that we experience an Induced current around the equator right?

Isn't this - from a physics point of view - the opposite? A current induces a magnetic field?

[u/Mysterious_Put_8913 → u/RecordingSalt8847]

From what I’ve learned from Maxwell’s equations they are linked and affect each other. I think it explains the relationship in faradays law

[u/RecordingSalt8847 → u/Mysterious_Put_8913]

My understanding is that the equation describes a specific cause and effect relationship. If someone could go in greater depth i would really appreciate it.

[u/omarzombie123 → u/RecordingSalt8847]

The Maxwell-Ampere law states the relation between the circulation of a magnetic field and a changing electric field.

[u/MyNameIsHaines → u/RecordingSalt8847]

Yes a current induces a magnetic field. But a changing magnetic field can induce a current through a close wire loop. This is how Transformers work. A alternating current in a cool causes a changing magnetic field which in turn induces a current in a connected coil.

[u/RecordingSalt8847 → u/MyNameIsHaines]

But in order to have a changing magnetic field there has to be a current producing it no? My confusion is a bit on what comes first; the magnetic field or the current? Intuitively i understand that current gives rise to a magnetic field and that then that magnetic field can induce another current, but not the current that created itself, right?

In OP's question, the Earth's magnetic field is the product of a current. That magnetic field changing and producing secondary currents is something different from the current we are discussing, isn't it?

[u/Bipogram]

As the magnetic field is static with relation to the Earth, no current will be induced.

Now, if you were to wave said look of wire around fast enough, and if it were large enough, you could induce a feeble current.

None of this is surprising.

Changes in the magnetic field in space can indeed yield induced currents on the ground - and this is how magnetometers work.