Strength of Magnetic Fields
Science: KS3, topic 3.4.16
Magnetic Field Strength
The closer magnetic field lines are, the stronger the magnetic field. Coiling wire around an iron core increases the wire over a shorter distance. The magnetic field lines are in the same direction.
For a straight wire
- A straight wire carries a current.
- The magnetic field is strongest at the points closest to the wire.
- The magnetic field is weakest further away from the wire.
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For a coil of wire (solenoid)
- A solenoid is a coil of wire.
- The magnetic field inside a solenoid is strong and uniform.
Field outside solenoid
- Outside a solenoid, the magnetic field gets weaker.
- The magnetic field is weaker further from the solenoid.
Current and field strength
- Increasing the size of the current increases the strength of the magnetic field.
- The magnetic field is produced by a solenoid.
Test yourself on Strength of Magnetic Fields
Where is a magnetic field around a wire strongest?
Select the correct statement in each pair.
Why does coiling a wire into a solenoid produce a stronger magnetic field than a single straight wire?