Magnetism and Earth's magnetic field
Invisible magnetic fields point compass needles north, and the same effect can be created just by running a current through a wire.
Part of your national curriculum
- Physics: electricity and magnetism: Understand magnetic fields, including Earth's magnetism, compasses and the magnetic effect of a current
Lesson overview
What you'll learn in this lesson
Understand magnetic fields, including Earth's magnetism, compasses and the magnetic effect of a current
Key learning points
- • Magnetic fields
- • Earth's magnetism and compasses
- • The magnetic effect of a current
This lesson at a glance
- 24 minutes
- 14 parts to scroll through
- 3 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 14
Watch first
Magnetism and Earth's magnetic field
An English teaching video on this topic from Lammas Science. Watch it, then scroll down for the lesson.
In a nutshell
Understand magnetic fields, including Earth's magnetism, compasses and the magnetic effect of a current
Learning cycle
Part 2 of 14
Learning cycle 1 of 2
Part 1 · Magnetic fields
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 14
Learn
Magnetic fields
A magnetic field is the region around a magnet where a magnetic material or another magnet experiences a force. Field lines run from the north pole to the south pole outside the magnet, and are closest together (strongest) near the poles.
Explore the idea
Part 4 of 14
Learn
Earth's magnetism and compasses
The Earth behaves like a giant bar magnet, generated by the movement of molten iron in its outer core. A compass needle is a small magnet that aligns with Earth's magnetic field, pointing towards Earth's magnetic north.
Quick check
Part 5 of 14
Quick check
Which way do magnetic field lines run outside a bar magnet?
Reset break
Part 6 of 14
Pause
That's sitting 1 of 2 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 7 of 14
Quick check
What causes Earth's magnetic field?
Learning cycle
Part 8 of 14
Learning cycle 2 of 2
Part 2 · The magnetic effect of a current
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 9 of 14
Learn
The magnetic effect of a current
A current flowing through a wire creates a magnetic field around it. Coiling the wire into a solenoid concentrates this field, and adding an iron core creates a stronger electromagnet — the basis of devices like electric bells, motors and cranes for lifting scrap metal.
Quick check
Part 10 of 14
Quick check
How can you make an electromagnet stronger?
Challenge round
Part 11 of 14
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Challenge round
Part 12 of 14
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
A ____ field is the region around a magnet where a magnetic material or another magnet experiences a force.
Mastery quiz
Part 13 of 14
Marked quiz
End of lesson quiz: Magnetism and Earth's magnetic field
3 questions, marked with the reasoning shown. No timer.
1. Which way do magnetic field lines run outside a bar magnet?
2. What causes Earth's magnetic field?
3. How can you make an electromagnet stronger?
Lesson round-up
Part 14 of 14
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 3 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the school greenhouse failed
A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.
The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.
The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.
Written for Good Learning Co.
Reading questions
- Name the variable the club changed the second time, and one variable they kept the same.
- Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
- Write a conclusion for the club's report, saying how far the evidence supports it.
Method and results
WritingWrite the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
WritingExplain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
DiagramDraw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
ReadingRead the lesson text again and write the key ideas in your own words.
Half a page of notes
Saved as you type.
Part 1 of 14 · Watch & discover
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Understand magnetic fields, including Earth's magnetism, compasses and the magnetic effect of a current