PHYSICS [1 Mark Question Answer]

Artificial magnets are preferred over natural magnets because natural magnets are weak and often irregular in shape, they can readily be magnetised and demagnetised by turning the current on or off in the coil.

1. By hammering the magnet repeatedly.
2. By rough handling
3. By heating.

Pieces of iron or other materials are made magnets by rubbing them with natural magnets (or bypassing direct current through a wire wound around them). This is how artificial magnets are made.

Magnetic keepers are used for storing magnets. Magnetic keepers are small pieces .of soft iron.

A magnet always rests in North and South direction, i.e. N-end always towards North of Earth and S-end towards South of Earth.

The strength of the electromagnet can be increased:

1. by increasing the current in the coil, and
2. by increasing the total number of turns of the coil.

Take iron filling on a piece of paper. Bring a bar magnet near it. The iron filling will cling to it. It shows the attractive property of the magnet.

The substances which have the property of attracting iron, are called magnets.

Electric bells, electric motor, telephones, loudspeakers, and generators are few common appliances that use electromagnets.

The region around a magnet where its magnetic force can be experienced is called the magnetic field.

An imaginary line (PQ) bisecting the effective length of a magnet is called the magnetic equator of the magnet.

The distance (NS) between the north pole and south pole of a magnet is called the length or effective length of the magnet.

An imaginary line (XY) passing through the magnetic north pole and magnetic south pole of a bar magnet is called its magnetic axis.

Examples of magnetic substances – Iron, nickel, cobalt
Examples of non-magnetic substances – Plastic, wool, wood, paper, rubber, etc.

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.

The directive property of the magnet is used in a compass for navigation purposes as the magnetic needle inside the compass always rests in the geographical north-south direction.

Iron is a magnetic substance because it gets attracted by a magnet.

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

No, because like poles repel each other when two magnetic are brought close to each other.

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

Substances such as iron, nickel, cobalt, or their alloys that get attracted by a magnet are called magnetic substances.