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What is a difference between the magnetic fields of a regular bar magnet and an electromagnet?
a. a bar magnet's field is temporary, but an electromagnet's is permanent.
b. a bar magnet's field is permanent, but an electromagnet's is temporary.
c. a bar magnet is made of iron, but an electromagnet is made of plastic.
d. there is always an electric current flowing around an electromagnet.
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What is a difference between the magnetic fields of a regular bar magnet and an electromagnet?
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