Mammoth Memory

Strength of an electromagnet (Number of coils)

The strength of an electromagnet changes with the number number of coils of the wire.

The way to judge if more turns on a electromagnet produces a stronger magnetic force is to count how many paperclips the different number of coils pick up.

NOTE: This is also a great test to judge between the strength of two magnets.

An electromagnet picking up 3 paperclips

Here this electromagnet can only pick up three paperclips. If you add a fourth paperclip they all fall off.

An electromagnet picking up 5 paperclips

Here, with more turns of wire on the nail, the electromagnet can pick up five paperclips.

 

Conclusion

More turns = More strength

NOTE: You could also demonstrate how much further away a compass is affected by an electromagnet with more coils as another method to determine strength.

 

NOTE: The strength of an electromagnet is directly proportional to not only the current but the number of windings. Double the number of windings doubles the strength of the magnet.

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