# Extending the range of electro magnets? Can it be done?

## Main Question or Discussion Point

Is it possible to extend the range of an electromagnet? How would one do this?

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Nabeshin
Extend the range? Why do you mean? If by range you mean the distance at which it exerts a force, well, that's already infinity.

Danger
Gold Member
You can extend the reach by using an intermediary piece of metal, along the line of picking up a chain of paper clips.

russ_watters
Mentor
Crank up the juice.

cepheid
Staff Emeritus
Gold Member
Extend the range? Why do you mean? If by range you mean the distance at which it exerts a force, well, that's already infinity.
Ummm...yeah. I'm pretty sure he means he distance at which it produces a measurable, non-negligible force that is capable of doing something. If so, then russ waters is right. The larger the current in the coil, the stronger the magnetic field will be at any given distance.

Crank up the juice.
Ummm...yeah. I'm pretty sure he means he distance at which it produces a measurable, non-negligible force that is capable of doing something. If so, then russ waters is right. The larger the current in the coil, the stronger the magnetic field will be at any given distance.
Yah this is more along the lines that I was meaning. Crankin it would work for sure, so I assume from the responses though there are no designs that would effects this?

well if you can design the electromagnet by yourself - the force should be proportional to the number of turns of the coil

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An electromagnet with iron as a core will saturate at some value of the field strength. At that point you get no more help from the iron in increasing the field strength and cranking up the juice will have much less effect. At this point it's better to increase the diameter of the core and the coil. (and crank up the juice as well to keep the field strength constant).
a 1 cm^2 coil with a field strength of 1T will produce the same force at 5 cm as a 100 cm^2 coil with the same field strength will at 50 cm.

An electromagnet with iron as a core will saturate at some value of the field strength. At that point you get no more help from the iron in increasing the field strength and cranking up the juice will have much less effect. At this point it's better to increase the diameter of the core and the coil. (and crank up the juice as well to keep the field strength constant).
a 1 cm^2 coil with a field strength of 1T will produce the same force at 5 cm as a 100 cm^2 coil with the same field strength will at 50 cm.
So thicker diamater = stronger magnet. What about increasing the legth of the iron core/coil? Does that make any changes? Are there better core materials than iron?