IGCSE Physics 4.1 Magnetism MCQs – 30 Practice Questions with Answers (Cambridge 0625)
Free practice MCQs for Cambridge IGCSE Physics (0625) Section 4.1, Simple Phenomena of Magnetism, covering Core material plus the Supplement items tagged in the questions. This section is qualitative – there are no equations to learn – so work through each question carefully, then open the Show Answer toggle to check the explanation.
Key facts recap: like poles repel and unlike poles attract; repulsion is the only certain test for a magnet; outside a magnet the field lines run from the N pole to the S pole and are closest together where the field is strongest. For the full revision sheet, see the IGCSE Physics Formula Sheet.
Poles, Attraction & Magnetic Materials
Q1. The north poles of two bar magnets are brought close together. What happens?
- (A) They attract each other strongly
- (B) They repel each other
- (C) Nothing happens, because only opposite poles affect each other
- (D) Both magnets lose their magnetism
Show Answer
Answer: B – Like poles repel: N repels N and S repels S. Unlike poles (N and S) attract.
Q2. An unlabelled metal bar is attracted by both ends of a known bar magnet. What can be concluded about the metal bar?
- (A) It is made of a magnetic material, but it is not necessarily a magnet itself
- (B) It must be a magnet with a north pole at each end
- (C) It must be a non-magnetic material
- (D) It must carry an electric charge
Show Answer
Answer: A – A magnet attracts unmagnetised magnetic material at either pole, so attraction by both ends only proves the bar is a magnetic material such as iron or steel. Attraction alone cannot prove that the bar is itself a magnet.
Q3. Which observation is the ONLY certain proof that a metal bar is a magnet?
- (A) It attracts iron filings
- (B) It attracts both ends of a known magnet
- (C) It picks up a heavier load at its ends than at its centre
- (D) It repels one end of a known magnet
Show Answer
Answer: D – Repulsion can only happen between two like poles, so it needs two magnets. Attraction happens between a magnet and unmagnetised magnetic material too, so attraction is never proof. Repulsion is the only certain test.
Q4. Which of these materials is NOT attracted by a magnet?
- (A) Iron
- (B) Nickel
- (C) Aluminium
- (D) Cobalt
Show Answer
Answer: C – Iron, steel, nickel and cobalt are magnetic materials and are attracted to a magnet. Aluminium, copper and wood are non-magnetic and are not attracted.
Q5. Where is the magnetic effect of a bar magnet strongest?
- (A) At the poles, near the ends of the magnet
- (B) At the centre of the magnet
- (C) Along the flat sides of the magnet
- (D) It is equal at every point on the magnet
Show Answer
Answer: A – The magnetism is concentrated at the poles, near the ends. Iron filings cling most thickly at the poles and hardly at all at the centre.
Q6. A bar magnet is cut in half across its middle. What is each half?
- (A) A piece with only a north pole, and a piece with only a south pole
- (B) A complete magnet with its own north pole and south pole
- (C) Completely demagnetised
- (D) A magnet with two north poles
Show Answer
Answer: B – Isolated poles do not exist. Cutting a magnet always produces smaller complete magnets, each with an N pole and an S pole; new poles form at the cut faces.
Q7. An unmagnetised iron nail is held near the north pole of a strong magnet, without touching it. The end of the nail nearest to the magnet becomes…
- (A) a north pole
- (B) completely demagnetised
- (C) electrically charged
- (D) a south pole, so the nail is attracted
Show Answer
Answer: D – This is induced magnetism. The magnet induces the opposite pole in the nearest end of the nail (S near N), so the nail is attracted. The induced magnetism in soft iron disappears when the magnet is removed.
Q8. Which pair consists of two magnetic materials?
- (A) Copper and steel
- (B) Iron and aluminium
- (C) Steel and nickel
- (D) Cobalt and wood
Show Answer
Answer: C – Steel and nickel are both magnetic materials (as are iron and cobalt). Copper, aluminium and wood are non-magnetic, so every other pair contains a non-magnetic material.
Q9. A magnet lifts a chain of steel paper clips, each clip holding on to the next one. Why does each clip hold the next?
- (A) Each clip has been permanently magnetised at the factory
- (B) Each clip becomes an induced (temporary) magnet while it is in the field of the one above it
- (C) An electric current flows through the chain of clips
- (D) The clips are glued together by friction
Show Answer
Answer: B – Each clip is magnetised by induction in the field of the magnet (or the clip above it), with its induced pole attracting the next clip. When the magnet is taken away, the chain falls apart because the induced magnetism is lost.
Q10. A bar magnet is suspended freely by a thread so that it can turn. It comes to rest pointing approximately…
- (A) north–south
- (B) east–west
- (C) towards the Sun
- (D) in a different random direction each time
Show Answer
Answer: A – The Earth’s magnetic field turns a freely suspended magnet so that it lines up roughly north–south. This is the principle of the magnetic compass; the end that points roughly north is called the north-seeking (N) pole.
Magnetising & Demagnetising
Q11. A steel bar is magnetised by the stroking method using one pole of a bar magnet. Which procedure is correct?
- (A) Rub the magnet backwards and forwards along the bar many times
- (B) Stroke with the north pole in one direction, then with the south pole back the other way
- (C) Stroke repeatedly in one direction only, lifting the magnet well clear of the bar at the end of each stroke
- (D) Leave the magnet resting still on top of the bar overnight
Show Answer
Answer: C – Stroking must always be in the same direction with the same pole, and the magnet is lifted away at the end of each stroke before being brought back to the start. Stroking back and forth would scramble the effect and not magnetise the bar properly.
Q12. A steel bar is placed inside a solenoid. How is the bar magnetised?
- (A) Pass a.c. through the solenoid and slowly reduce it to zero
- (B) Connect the solenoid to a battery, then disconnect it before the bar is put in
- (C) Hammer the bar while it is inside the solenoid
- (D) Pass a steady d.c. current through the solenoid while the bar is inside
Show Answer
Answer: D – A steady direct current makes the solenoid act like a strong bar magnet and magnetises the bar inside it. Slowly reducing a.c. to zero (option A) is a demagnetising method, not a magnetising one.
Q13. Which of these treatments can demagnetise a permanent magnet?
- (A) Storing it with soft iron keepers across its poles
- (B) Heating it strongly
- (C) Stroking it in one direction with another magnet
- (D) Keeping it pointing east–west in a steel box
Show Answer
Answer: B – Strong heating destroys the magnetism (the thermal energy jumbles the alignment inside the material). Hammering, dropping and a slowly withdrawn a.c. field also demagnetise. Keepers (option A) do the opposite – they help a magnet keep its magnetism in storage.
Q14. A magnet is demagnetised using a solenoid carrying alternating current. What should be done?
- (A) Slowly withdraw the magnet from the solenoid while the a.c. is still flowing
- (B) Switch off the current first, then take the magnet out
- (C) Push the magnet in and out of the solenoid as fast as possible
- (D) Leave the magnet in the centre of the solenoid with the current on
Show Answer
Answer: A – As the magnet is slowly pulled away, it experiences an alternating field that gets weaker and weaker, leaving its internal alignment completely jumbled – demagnetised. Switching off while the magnet is still inside would freeze it in whatever the field was at that moment.
Q15. Why is steel used for permanent magnets instead of pure iron?
- (A) Steel is much easier to magnetise than iron
- (B) Steel always becomes a stronger magnet than iron
- (C) Steel keeps its magnetism, while iron loses its magnetism easily
- (D) Steel is not attracted to other magnets, so it is safer
Show Answer
Answer: C – Steel is a hard magnetic material: it is harder to magnetise than iron, but once magnetised it keeps its magnetism. Iron is a soft magnetic material – easily magnetised but just as easily demagnetised.
Q16. The core of the electromagnet in an electric relay switch is made of soft iron. Why?
- (A) Soft iron keeps its magnetism permanently between uses
- (B) Soft iron magnetises when the current is on and loses its magnetism quickly when the current is switched off
- (C) Soft iron never becomes magnetised, so the switch cannot stick
- (D) Soft iron has a very high electrical resistance
Show Answer
Answer: B – A relay electromagnet must attract the switch contact when current flows and release it as soon as the current stops. Soft iron is ideal because it gains and loses magnetism very quickly; a steel core would stay magnetised and the switch would stick on.
Q17. Hammering a magnet repeatedly can destroy its magnetism. This works because the hammering… [Supplement]
- (A) knocks the poles off the ends of the magnet
- (B) heats the magnet until it melts
- (C) removes the magnetic material from the bar
- (D) shakes the magnetic domains inside the material out of alignment
Show Answer
Answer: D – In a magnetised bar the domains (small magnetic regions) line up in one direction. Violent hammering jumbles them back into random directions, so their effects cancel and the bar is demagnetised.
Q18. What is meant by a temporary magnet?
- (A) A magnet that loses its magnetism as soon as the magnetising influence is removed
- (B) A magnet that works for only one day
- (C) Any magnet made from steel
- (D) A magnet that cannot attract iron or steel
Show Answer
Answer: A – Soft magnetic materials such as iron make temporary magnets – they are magnetised only while a magnet or current is acting on them. Hard materials such as steel make permanent magnets that keep their magnetism.
Q19. Which choice of material is correct?
- (A) Compass needle – soft iron, so it can swing freely
- (B) Electromagnet core in a scrapyard crane – steel, so the load is never dropped
- (C) Permanent bar magnet – steel, because it keeps its magnetism
- (D) Relay switch core – steel, because it must stay magnetised
Show Answer
Answer: C – Permanent magnets are made of hard magnetic steel. Compass needles must be permanent magnets (not soft iron), and electromagnet cores – in cranes and relays – must be soft iron so the magnetism switches off with the current.
Q20. A steel bar is stroked many times from its left end to its right end, always using the south pole of the stroking magnet. The right-hand end of the bar becomes…
- (A) a south pole
- (B) a north pole
- (C) a neutral point
- (D) completely demagnetised
Show Answer
Answer: B – In stroking, the end of the bar where the stroking pole finishes (and is lifted away) gains the opposite polarity to the stroking pole. Stroking with an S pole leaves an N pole at the right-hand end.
Magnetic Fields & Compasses
Q21. Outside a bar magnet, magnetic field lines are drawn going…
- (A) from the north pole to the south pole
- (B) from the south pole to the north pole
- (C) out of both poles, meeting in the middle
- (D) into both poles from the surroundings
Show Answer
Answer: A – By convention, field lines outside a magnet leave the N pole and enter the S pole (they show the direction of the force on a free north pole). Inside the magnet they continue from S back to N, forming closed loops.
Q22. On a field line diagram for a bar magnet, the magnetic field is strongest where…
- (A) the field lines are far apart
- (B) the field lines are perfectly straight
- (C) the field lines are closest together, near the poles
- (D) no field lines have been drawn
Show Answer
Answer: C – The closer together the field lines, the stronger the field. Around a bar magnet the lines are crowded near the poles, which is exactly where the field – and the force on magnetic materials – is strongest.
Q23. Iron filings are sprinkled on a card held over a bar magnet and the card is tapped gently. The filings…
- (A) measure the field strength in tesla
- (B) all slide to the centre of the magnet
- (C) point only towards the north pole
- (D) line up along the magnetic field lines, revealing the shape of the field pattern
Show Answer
Answer: D – Each filing becomes a tiny induced magnet and turns to line up with the field, so together they trace out the field pattern. Filings show the shape of the field but not its direction – a compass is needed for that.
Q24. A small plotting compass is placed at a point near a bar magnet. The compass needle settles so that it…
- (A) always points towards geographical north, ignoring the magnet
- (B) lies along the magnetic field line at that point, with its north pole pointing in the direction of the field
- (C) points straight at the nearest pole of the magnet, whichever pole it is
- (D) lies at right angles to the magnetic field line
Show Answer
Answer: B – A compass needle is a small magnet that lines itself up with the magnetic field at its position. Its N pole points in the field direction, which is why compasses are used to trace field lines step by step.
Q25. The north pole of a compass needle points roughly towards the geographic north. This is because…
- (A) there is a magnetic north pole at the geographic north that attracts it
- (B) the needle is electrically charged and the Earth carries the opposite charge
- (C) the Earth’s magnetic pole near the geographic north is actually a magnetic south pole, which attracts the compass needle’s north pole
- (D) gravity pulls the north end of the needle downwards towards the north
Show Answer
Answer: C – Opposite poles attract. Since the N pole of the compass is attracted towards the Arctic region, the Earth’s magnetic pole there must behave as a magnetic south pole. It is only called the “north magnetic pole” because of where it is.
Q26. Two identical bar magnets are placed in a line with their north poles facing each other across a small gap. Midway between the poles there is a neutral point. A neutral point is a point where… [Supplement]
- (A) the two magnets touch each other
- (B) field lines cross over each other
- (C) iron filings collect in the thickest layer
- (D) the fields of the two magnets are equal and opposite, so the resultant magnetic field is zero
Show Answer
Answer: D – Between two facing like poles, the fields push against each other and cancel at one point – the neutral point. The field lines from each magnet bend away and never enter the other magnet, showing the repulsion. A compass placed exactly at the neutral point feels no turning effect from the magnets.
Q27. A north pole and a south pole of two bar magnets face each other across a small gap. Which description of the field in the gap is correct?
- (A) Field lines run across the gap from the north pole to the south pole, and the poles attract
- (B) Field lines bend away from the gap because the poles repel
- (C) The fields cancel everywhere in the gap, so there is no field there
- (D) Field lines form closed circles inside the gap
Show Answer
Answer: A – With unlike poles facing, the field lines pass straight across the gap from N to S and the two fields reinforce each other in the gap. The pattern in the gap looks like the field of a single magnet, matching the attraction between the poles.
Q28. Which statement about neutral points is correct? [Supplement]
- (A) A neutral point is found where two magnetic fields reinforce each other
- (B) Every magnet has a neutral point exactly at its centre
- (C) At a neutral point the resultant magnetic field is zero, so a compass there is affected only by any other field present, such as the Earth’s
- (D) Field lines are most crowded together at a neutral point
Show Answer
Answer: C – A neutral point occurs where two fields cancel exactly (for example between two like poles, or where a magnet’s field balances the Earth’s field). The resultant field there is zero – the opposite of the poles, where field lines are most crowded and the field is strongest.
Q29. A sensitive instrument needs magnetic shielding – protection from outside magnetic fields. The best way to shield it is to surround it with…
- (A) a thick plastic case
- (B) a layer of aluminium foil
- (C) a copper sheet
- (D) a soft iron enclosure, which gives the field lines an easy path around the instrument
Show Answer
Answer: D – Soft iron is very easily magnetised, so field lines prefer to travel through the iron walls rather than through the space inside – the enclosure diverts the field around the instrument. Plastic, aluminium and copper are non-magnetic and give no shielding.
Q30. A student plots the field lines around a bar magnet using a small compass. Which is the correct method?
- (A) Sprinkle iron filings first, then push the compass through them
- (B) Place the compass near a pole, mark dots at each end of the needle, move the compass so one end is at the far dot, and repeat, then join the dots
- (C) Rotate the magnet a quarter turn after marking each dot
- (D) Hold the compass high above the magnet so the Earth’s field has no effect
Show Answer
Answer: B – The dot-and-step method traces one field line at a time: dots mark the two ends of the needle, the compass is moved along until its tail reaches the last dot, and the joined dots form a field line. Starting lines at several points near the pole builds up the whole pattern, with arrowheads in the direction the needle’s N pole points.
Keep practising: Explore more free MCQs for every board on our Physics MCQs hub, and keep the IGCSE Physics Formula Sheet open while you revise – magnetism returns in the electromagnetism sections, where field patterns decide how motors and generators behave.
All questions on this page are original practice questions written for QuaidianPoint. They are not Cambridge past-paper questions.