Which of the following is true about Electromagnets? When the current is shut off, the magnetic field disappears.
they do not easily lose their magnetism.
they are naturally-occurring magnets
All of the above
None of the above​

A. When the current is shut off, the magnetic field disappears.

Explanation:

Electromagnetism is a method in which magnetism is obtained from an electric current. It is an artificial way of producing a strong magnetic fields due to the flow of current.

Since the magnetic effect observed is due to the flow of an electric current, so when the current is shut off, the magnetic field disappears.

It has a wide range of applications in manufacturing industries, electric bells, induction coil etc.

multiple

true tan speed = ang vel x radius