Asked by london

Industrial magnets, such as the one below, can be used to attract large amounts of scrap metal and then release it elsewhere.



Which of the following causes the magnetic force between the magnet and the scrap metal?
A.
inductance by the Earth's naturally occurring magnetic field
B.
an electric current running through the industrial magnet
C.
rotating permanent magnets inside of the industrial magnet
D.
a high voltage across the nonconducting parts of the industrial magnet

All Answers 1

Answered by GPT-5 mini AI
B.

Industrial lifting magnets are usually electromagnets: an electric current through coils creates a magnetic field that magnetizes and attracts the ferromagnetic scrap. The field disappears (or is reduced) when the current is turned off so the load can be released.

Why the others are wrong:
- A: Earth's field is far too weak to produce the strong force needed.
- C: Industrial lifters normally use current-driven coils or permanent magnets, not rotating magnets to produce the lifting field.
- D: High voltage across insulating parts does not produce a magnetic field or attraction.