AQA · GCSE · Physics
Course version: 8463 · Version from Sept 2016
A magnetic compass contains a small bar magnet. The Earth has a magnetic…
Full specification wording
Magnetic fields: A magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field.
A magnetic compass is a small bar magnet balanced on a pivot so that it can turn freely.
Checked against the AQA 8463 specification (opens in a new tab) on .
- Point 6 of 6
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
A magnetic compass is a small bar magnet balanced on a pivot so that it can turn freely. With no other magnet nearby it lines up with the Earth's magnetic field, so its north seeking pole points roughly towards geographic north, and that is where the name comes from. Bring a magnet or a current carrying wire close and the much stronger local field wins, so the needle swings to follow that instead; a change in the direction of the needle is the evidence that a magnetic field has been produced. The fact that a compass works anywhere on the planet is evidence that the Earth generates its own field, produced by motion in its liquid iron and nickel core.
What earns the marks
- Stating that a compass contains a small bar magnet that is free to rotate.
- Stating that the needle lines up with the direction of the magnetic field it is in.
- Stating that the Earth has a magnetic field, so a compass away from other magnets points north.
- Stating that a change in the direction of the needle shows that a magnetic field is present.
Common mistakes and how to put them right
Saying the needle points exactly at the geographic north pole.
Saying the compass is attracted towards north rather than aligning with the field.
Attributing the Earth's field to iron ore in the crust rather than the liquid core.
Expecting the needle to keep pointing north when a strong magnet is placed beside it.
Exam tips
- The credited sentence is that the changing direction of the compass needle shows a field has been produced.
- Say the needle aligns with the field, rather than that it is pulled by it.
- Mention the core when a question asks what the compass tells us about the Earth.
Try the lesson
The start of the Magnetic fields: A magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field. lesson, made from checked teaching notes for this specification point.
Have a go first
What does a magnetic compass contain that allows it to respond to the Earth’s magnetic field?
Listen
A magnetic compass is a small bar magnet balanced on a pivot so that it can turn freely. With no other magnet nearby it lines up with the Earth's magnetic field, so its north seeking pole points roughly towards geographic north, and that is where the name comes from. Bring a magnet or a current carrying wire close and the much stronger local field wins, so the needle swings to follow that instead; a change in the direction of the needle is the evidence that a magnetic field has been produced. The fact that a compass works anywhere on the planet is evidence that the Earth generates its own field, produced by motion in its liquid iron and nickel core. A strong answer earns marks for these points. stating that a compass contains a small bar magnet that is free to rotate. stating that the needle lines up with the direction of the magnetic field it is in. stating that the Earth has a magnetic field, so a compass away from other magnets points north. stating that a change in the direction of the needle shows that a magnetic field is present. Exam tip: The credited sentence is that the changing direction of the compass needle shows a field has been produced.
Key words
Say what each word means before you turn the card.
magnetic compass
Try answering aloud or in your head before turning the card.
small bar magnet
Try answering aloud or in your head before turning the card.
Earth's magnetic field
Try answering aloud or in your head before turning the card.
alignment with a field
Try answering aloud or in your head before turning the card.
See every definition
- magnetic compass
- Contains a small bar magnet balanced on a pivot so that it can turn freely.
- small bar magnet
- The part inside a compass that is free to rotate and lines up with the direction of the magnetic field it is in.
- Earth's magnetic field
- The field the Earth generates, produced by motion in its liquid iron and nickel core, which a compass away from other magnets lines up with.
- alignment with a field
- The needle lines up with the direction of the magnetic field it is in rather than being pulled by it.
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Magnetic fields: A magnetic compass contains a small bar magnet. The Earth has a magnetic field. The compass needle points in the direction of the Earth’s magnetic field.
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge