In the single-touch method of making a magnet, ................. (one/two) bar magnet(s) is/are used.

For making a magnet using the double-touch method, .................. (one/two) bar magnet(s) is/are required.

Single-touch and double-touch methods of making a magnet

Magnetic length of a bar magnet is

The magnetism of a bar magnet is due to

In the electrical method of making a magnet, a magnetic material is magnetized using a/an .................. (bar magnet/electric current).

State two properties of a bar magnet.

The figures above show methods of making a magnet. Name the methods.

The metal used to make temporary magnets

The magnetic field lines inside a bar magnet

With a standard rectangular bar magnet the time period of a vibration magnetometer is 4 s. The bar magnet is cut parallel to its length into four equal pieces. The time period of vibration magnetometer when one piece is used (in second) (bar magnet breadth is small) is