PHYSICS [2 Mark Question Answer]

Because of the attractive property of a magnet. A magnet attracts magnetic substances by exerting a force called magnetic force. This keeps the door of a refrigerator closed tightly.

An electromagnet is a temporary magnet because it behaves like a magnet only till the current is passed through it. When the current is stopped, it stops behaving like a magnet.

Magnets must be handled with care or else they lose their magnetic properties and become weak. To prevent a magnet from becoming demagnetized, magnet should not be handled roughly, hammered, dropped, heated. It should be stored using magnetic keepers.

Directional property of magnets states that a freely suspended magnet always points towards the geographical north-south direction. Eveiy magnet, irrespective of its shape, has a north pole and a south pole.

Magnetic poles always exist in pairs and cannot exist independently. If a bar magnet is broken into two or more pieces, each of them will have a north pole and a southpole. Hence, it is impossible to obtain a piece of magnet with only one magnetic pole.

Magnets that are made by humans from magnetic substances are called artificial magnets. They can be made in different shapes and sizes like bar magnet, horseshoe magnet, etc.

We can control and change the magnetic force of the electromagnet by controlling the amount of electric current passed to it by an electric generator. When the power is on, the magnetic field (force) will attract the junk to it. When the junk is to be dropped somewhere, the power is cut to the electromagnet and the junk drops. If permanent magnet would be used, it would get difficult to detach the junk from it.