- A steel bar

- A solenoid (an electrical coil)

- A power source (a battery or power supply)

- Connecting wires

Procedure:

1. Connect the solenoid to the power source. Make sure the polarity of the connections is correct (i.e., the positive terminal of the power source is connected to the positive terminal of the solenoid, and the negative terminal of the power source is connected to the negative terminal of the solenoid).

2. Place the steel bar inside the solenoid. The steel bar should be positioned along the axis of the solenoid, and it should not touch the sides of the solenoid.

3. Turn on the power source. This will cause an electrical current to flow through the solenoid, creating a magnetic field.

4. Leave the steel bar in the solenoid for a few minutes. This will allow the steel bar to become magnetised.

5. Turn off the power source.

6. Remove the steel bar from the solenoid. The steel bar will now be magnetised.

How it Works:

When an electrical current flows through a solenoid, it creates a magnetic field. This magnetic field is strongest inside the solenoid, and it decreases in strength as you move away from the solenoid. The steel bar is magnetised when it is placed inside the solenoid because the magnetic field of the solenoid aligns the magnetic domains of the steel bar. When the power source is turned off, the magnetic field of the solenoid disappears, but the magnetic domains of the steel bar remain aligned, and the steel bar remains magnetised.

Applications:

Solenoids are used in a variety of applications, including:

- Electric motors

- Generators

- Magnetic resonance imaging (MRI) machines

-Loudspeakers

-Magnetic levitation (maglev) trains