Which material can be magnetised using the strong magnetic field inside a solenoid?

The correct option is Soft iron.

Step-by-Step Explanation:

1. Understanding Magnetisation:
Magnetisation is the process of converting a non-magnetic material into a magnet by aligning its internal magnetic domains. This is usually achieved by placing the material inside a strong external magnetic field.

2. The Role of a Solenoid:
A solenoid consists of a coil of insulated copper wire wound closely in the shape of a cylinder. When an electric current passes through the solenoid, it behaves like a bar magnet, producing a strong, uniform magnetic field inside its core.

3. Magnetic Properties of Materials:
Different materials respond differently to an external magnetic field:
- Ferromagnetic materials (like iron, nickel, and cobalt) have a high magnetic susceptibility. They get strongly magnetised when placed inside a magnetic field.
- Soft iron is a prime example of a ferromagnetic material. It has high permeability, meaning it easily conducts magnetic fields and gets magnetised very quickly when placed inside a solenoid. Furthermore, it loses its magnetism quickly once the current is switched off, making it ideal for making temporary magnets (electromagnets).
- Aluminum is a paramagnetic material, meaning it is only weakly attracted by a magnetic field and cannot be effectively magnetised.
- Copper is a diamagnetic material, which slightly repels magnetic fields and cannot be magnetised.
- Plastic is a non-magnetic insulator and does not have any magnetic properties, so it cannot be magnetised at all.

Therefore, soft iron is the suitable material to be magnetised using the strong magnetic field inside a solenoid.