Primary 4 · Science · Interactions: Magnets
Interactions: Magnets questions for Primary 4 Science
10 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- Making a magnet
- Magnetism through materials
- Destroying magnetism
- Testing strength fairly
- The compass
- Storing magnets
- Where a magnet is strongest
- Naming a method
- Naming the strongest part
- Applying the ideas
| Magnet | Distance at which the clip first moved (cm) |
|---|---|
| P | 2.0 |
| Q | 4.5 |
| R | 1.2 |
| S | 3.1 |
Answers and explanations for all 10 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
How is a steel nail turned into a magnet by the stroke method?
Answer: by stroking it many times with one pole of a magnet, always in the same direction
The nail has to be stroked repeatedly with the same pole, always in the same direction. Going back and forth would cancel the effect out.
In the set-ups above, the clip moved when the magnet moved in A but not in B. What does this show?
Answer: Magnetism passes through card but is blocked by iron.
A magnet does not need to touch what it attracts. Its force reaches through card, but an iron sheet takes up the magnetism itself and shields the clip.
Which two of these would weaken a bar magnet?
Answer: A and B only
Knocking and heating both disturb a magnet and weaken it. Keepers and dry storage are how magnets are protected.
Based on the table above, which magnet is the strongest?
Answer: Q
A stronger magnet can move the clip from further away. Q acted at 4.5 cm, further than any of the others.
Why does a compass needle always come to rest pointing the same way?
Answer: The needle is a magnet, and the Earth acts like a huge magnet that pulls it into line.
A compass needle is a light magnet free to turn. The Earth behaves as a giant magnet, so the needle lines up with it and settles pointing north.
Which two of these are sensible ways to keep a pair of bar magnets strong?
Answer: A and B only
Magnets are stored in pairs with unlike poles together and keepers across the ends, which holds their magnetism in place. Heat and knocks both destroy it.
A bar magnet is dipped into a tray of iron filings. Where do most of the filings stick?
Answer: at the two ends
A magnet is strongest at its poles, which are at the two ends, so that is where the filings cluster.
A steel needle is turned into a magnet by being stroked repeatedly with one pole of a magnet. What is this method called? The ______ method.
Answer: stroke
Making a magnet by stroking it with another magnet is the stroke method.
The two ends of a bar magnet attract far more strongly than the middle does. What are these two ends called?
Answer: poles
The two ends of a magnet, where it is strongest, are its poles.
A fridge door closes with a soft click and stays shut. Why is a magnet used rather than a catch?
Answer: It holds the door shut without any moving parts to wear out or jam.
A magnetic strip pulls the steel door frame shut and seals it, with nothing to break, so the door works the same way after thousands of openings.