Magnetic Fields of Coils and Solenoids

This lesson provides a deeper look at the magnetic fields produced by coils and solenoids, including practical techniques for investigating these fields — as required by the Edexcel GCSE Physics specification (1PH0), Topic 8: Magnetism and Electromagnetism. You need to be able to describe field patterns, explain how to strengthen the field, and relate these concepts to real-world applications.

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The Magnetic Field of a Solenoid — In Detail

As covered earlier, a solenoid is a coil of wire that produces a magnetic field when current flows through it. This lesson examines the field in more detail.

Inside the Solenoid

• The field lines are straight, parallel and evenly spaced.
• This means the field is uniform — it has the same strength and the same direction at every point inside.
• The uniform field inside a solenoid is very useful for scientific and engineering applications (e.g. MRI scanners, particle accelerators).

Outside the Solenoid