Solenoid

Key Stage 4

Meaning

A solenoid is a coil of wire which produces a magnetic field, similar to that of a bar magnet, when it has an electrical current.

About Solenoids

Solenoids can be used to magnetise a magnetic material.

Solenoids have a uniform magnetic field inside the coil of wire and a non-uniform magnetic field outside the coil, similar to that of a bar magnet.

The magnetic field is strongest inside the coil.

Solenoids are not magnets themselves, but they are part of an electromagnet. To turn a solenoid into an electromagnet it needs a soft iron core.

The strength of a solenoid depends upon:

• The current in the coil - The greater the current the stronger the magnetic field.
• The number of coils - The greater the number of coils the stronger the magnetic field.