Which of the following in not a permanent magnet [ ] a) magnetic needle b) bar magnet c) electro magnet d) both a and b
Answers
Answer:
c) electro magnet
Explanation:
because a metal acts like a magnet when electricity is passed through it and when the flow of current is stopped it loses its magnetic property and becomes normal
Answer:
From the given options, electromagnet is not a permanent magnet.
Explanation:
a) Magnetic needle: It is most commonly used in compass. The needle is permanently magnetised so that it could point in the direction of north.
b) Bar magnet: A mostly rectangular piece of magnet with clear marking of north and south people is called bar magnet. It is a type of permanent magnet.
c) Electromagnet: It is mostly a metallic object like coil of wire that acts like a magnet when electricity is passed. It loses its magnetic ability as soon as the current is withdrawn.
Therefore, from the given options electromagnet is not a permanent magnet.