Question

Which of the following statements are true about the electromagnets?

• A. Their polarity can be reversed.
• B. Their magnetic strength cannot be altered.
• C. Electric current is the main source for their magnetism.
• D. They are temporary magnets.

Answer 1

Answer: (A), (C), (D)

The correct options are
A Their polarity can be reversed.
C Electric current is the main source for their magnetism.
D They are temporary magnets.

Electromagnets are a special class of magnets with properties such as:

• The polarity of the magnets can be reversed by reversing the current flow.
• As long as electric current flows through them, they behave as magnets, i.e. they are temporary magnets and hence can be switched on and off.
• By changing the amount of the current flowing through them, their magnetic properties like strength etc. can be changed.