What does not affect the strength of an electromagnet?

Unlike a permanent magnet, an electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength. ... Making the nail longer will not make the magnet stronger, unless you also add more turns to the coil.

electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength

explanation:

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the answer would be a