# Current and magnetic fields

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Hi, I want to know if an electromagnet is affected by the voltage or voltage+current. I thought that if the Newman motor runs on voltage, maybe an electromagnet would need only voltage, instead of voltage + current. I use a homemade (screw and copper wire) electromagnet.

Anybody knows?

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I'm pretty sure the equations for field are only dependent on Current (I), but it should be remembered that I and V are related.

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but it should be remembered that I and V are related.
Yes indeed $U=IR$
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U?

V is normally used for voltage or potential difference. U is used for energy (potential or internal).

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Darkshade's first equation is for ELECTRIC FIELD, which isn't really relevant, and it only applies in some special cases, it is not true in general.

For a coiled electromagnet, the quantity affecting the strength of the magnet is current, regardless of voltage.

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U?

V is normally used for voltage or potential difference. U is used for energy (potential or internal).

In my place we use U for voltage. That's on the books we have.

Darkshade's first equation is for ELECTRIC FIELD, which isn't really relevant, and it only applies in some special cases, it is not true in general.

OK great, but like I said that is part of electrostatics which is indeed kinda in ideal cases. I'm deleting it BTW.
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In my place we use U for voltage. That's on the books we have.
That's an unusual, although evidently not non-existant*, notation. What books do you have that use the notation (what subject and level are they)?

* using a double negative made the sentence sound better, IMHO.

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That's an unusual, although evidently not non-existant*, notation. What books do you have that use the notation (what subject and level are they)?

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In high school this term was used in our physics book, according to which we did all the stuff with electrostatics and electricity.

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