Exploring Magnets Part 2: MCQs (Q26–Q50)
Part 2 — Questions 26–50 (Magnetisation methods, field lines, Earth’s magnetism & applications)
26. Magnetisation means
A. Making a material warm only
B. Making a material acquire magnetic properties ← Correct answer: B
C. Turning metal into wood
D. Painting a material blue
Explanations:
A/C/D) Incorrect.
B) Correct — magnetisation aligns magnetic domains so a material behaves like a magnet.
27. Which method is commonly used to magnetise a bar of soft iron?
A. Cooling it quickly in ice
B. By placing it inside a coil carrying current (electromagnet) or stroking with a magnet ← Correct answer: B
C. Exposing it to sunlight only
D. Painting with silver paint
Explanations:
A/C/D) Incorrect.
B) Correct — electric current through a coil produces strong magnetic field; stroking aligns domains.
28. If a magnet is cut into many tiny pieces, each piece will
A. Become a non-magnetic powder
B. Become a small magnet with its own North and South poles ← Correct answer: B
C. All become pure North poles only
D. Turn into metal water
Explanations:
A/C/D) Incorrect.
B) Correct — each fragment is a smaller magnet with two poles.
29. Earth’s geographic North pole is close to the magnetic pole that is actually a
A. North magnetic pole (so compass points exactly to geographic north)
B. South magnetic pole (by convention, Earth’s magnetic north pole is actually a magnetic south pole) ← Correct answer: B
C. Electric pole
D. Non-magnetic point
Explanations:
A) Confusing—by physics convention a compass needle’s North pole points towards the magnetic south pole of Earth.
B) Correct — Earth’s magnetic pole near geographic north behaves like a magnetic south pole attracting the north pole of a compass.
C/D) Incorrect.
30. Which device uses magnets to convert electrical energy into motion?
A. Thermometer
B. Electric motor ← Correct answer: B
C. Refrigerator light only
D. A compass only
Explanations:
A/C/D) Incorrect.
B) Correct — motors use magnetic fields and current to produce rotation.
31. Which of these is an application of electromagnets?
A. Pencil sharpener only
B. Crane to lift scrap iron, bells, MRI, electric motors ← Correct answer: B
C. Growing plants magically
D. Making glass transparent
Explanations:
A/C/D) Incorrect.
B) Correct — electromagnets are widely used because field strength can be switched on/off.
32. Magnetic field lines are always drawn as
A. Broken lines only
B. Continuous closed loops ← Correct answer: B
C. Starting and ending at infinity only
D. Straight lines from sky to ground
Explanations:
A/C/D) Incorrect.
B) Correct — field lines form closed loops (no monopoles).
33. A compass needle near a current-carrying wire will
A. Be unaffected always
B. Deflect because current produces a magnetic field around the wire ← Correct answer: B
C. Start glowing red
D. Dissolve the wire
Explanations:
A/C/D) Incorrect.
B) Correct — Oersted showed that electric current creates magnetic field which affects compass needles.
34. Which of these statements is TRUE about refrigerator magnets?
A. They are superconductors only
B. They are small permanent magnets attached for holding items ← Correct answer: B
C. They are always made of glass only
D. They disappear when cold
Explanations:
A/C/D) Incorrect.
B) Correct — fridge magnets are permanent magnets usually made from flexible magnetic material.
35. The strength of an electromagnet can be increased by
A. Decreasing the number of turns of the coil
B. Increasing current or number of turns or using a soft iron core ← Correct answer: B
C. Removing the core
D. Wrapping the coil with paper only
Explanations:
A/C/D) These reduce or not affect strength.
B) Correct — more turns and higher current make field stronger; a soft iron core concentrates the field.
36. A magnetic compass will be useless near a large piece of iron because
A. The iron does not affect compass at all
B. The iron disturbs the local magnetic field and deflects the needle ← Correct answer: B
C. The compass will melt instead
D. The compass turns into iron permanently
Explanations:
A/C/D) Incorrect.
B) Correct — local magnetic materials distort Earth’s field causing compass errors.
37. Which of the following is true about magnetic field lines inside a magnet?
A. They run from North to South inside the magnet
B. They run from South to North inside the magnet ← Correct answer: B
C. There are no field lines inside a magnet
D. Field lines run in random disconnected pieces inside
Explanations:
A) Incorrect — convention: outside N→S, inside S→N.
B) Correct — completes closed loops.
C/D) Incorrect.
38. A steel needle becomes a temporary magnet when
A. Kept in sunlight only
B. Stroked with a magnet or placed near a strong magnet (induced magnetism) ← Correct answer: B
C. Thrown in water only
D. Painted black
Explanations:
A/C/D) No effect.
B) Correct — induction aligns domains making it temporary magnet.
39. Magnetic compass needles are usually made of
A. Rubber
B. Magnetised steel or other magnetic material ← Correct answer: B
C. Glass
D. Cotton
Explanations:
A/C/D) Non-magnetic.
B) Correct — needle must be magnetic to respond to field.
40. Magnetism in metals is due to
A. Random thermal motion only
B. Alignment of tiny magnetic domains inside material ← Correct answer: B
C. Presence of water molecules only
D. Colour of metal only
Explanations:
A/C/D) Incorrect.
B) Correct — domains (groups of atoms) align to produce net magnetism.
41. Magnetic field lines are closer near the poles because
A. Field is weaker near poles
B. Field is stronger near poles (lines denser where field is strong) ← Correct answer: B
C. Poles produce light only
D. There are no field lines near poles
Explanations:
A/C/D) Incorrect.
B) Correct — density of lines indicates field strength.
42. Which of the following is used to test whether a material is magnetic?
A. Taste it
B. Bring a magnet near it and see if it is attracted ← Correct answer: B
C. See if it dissolves in water only
D. Measure its temperature directly
Explanations:
A/C/D) Irrelevant tests.
B) Correct — practical test for magnetism.
43. An unmagnetised piece of iron is placed near a bar magnet. The iron becomes magnetised. This is known as
A. Permanent magnetisation always
B. Induced magnetism ← Correct answer: B
C. Radiation
D. Electrolysis
Explanations:
A) Induced magnetism may be temporary unless domains are locked in.
B) Correct — magnet is induced by proximity to magnet.
C/D) Irrelevant.
44. Which material would you choose for compass needle?
A. Plastic — not suitable
B. Soft steel or magnetised steel that holds magnetism but not too hard ← Correct answer: B
C. Wood — not magnetic
D. Pure copper — not magnetic
Explanations:
A/C/D) Non-magnetic.
B) Correct — needle must be magnetic and able to be magnetised.
45. Magnetic declination refers to
A. The temperature drop at night
B. Angle between geographic north and magnetic north at a place ← Correct answer: B
C. Decline of magnet’s colour
D. Amount of iron in soil only
Explanations:
A/C/D) Incorrect.
B) Correct — true north vs magnetic north differ by declination.
46. A toy car containing an electromagnet picks up paperclips when connected to a battery. If battery is removed, the clips fall off. This shows that the electromagnet is
A. Permanent magnet
B. Temporary (magnetism disappears without current) ← Correct answer: B
C. Not a magnet at all
D. Powered by solar energy only
Explanations:
A/C/D) Incorrect.
B) Correct — electromagnets are on/off with current.
47. Which of the following will NOT change the direction of magnetic field around a straight current-carrying wire?
A. Reversing the direction of current
B. Changing the wire’s colour ← Correct answer: B
C. Increasing current magnitude (direction remains same though strength changes)
D. Adding a soft iron core nearby (may affect local field)
Explanations:
A) Reverses field direction — changes it.
B) Correct — colour has no physical effect.
C) Strength changes, not direction (unless current reversed).
D) Core changes field distribution.
48. Why do iron filings show a pattern around a magnet?
A. They burn and make smoke patterns
B. Each filing becomes a tiny magnet and aligns along field lines ← Correct answer: B
C. Filing’s weight arranges them randomly
D. Magnetic field has no effect on filings
Explanations:
A/C/D) Incorrect.
B) Correct — induced magnetism in filings aligns them along the magnetic field.
49. Which of these is true for a horseshoe magnet?
A. It has no poles
B. Poles are brought closer to give stronger field between them ← Correct answer: B
C. It is made of wood only
D. It repels all metals always
Explanations:
A/C/D) Incorrect.
B) Correct — U-shape brings poles close increasing field strength in gap.
50. Which of the following is a correct safety note about magnets?
A. Strong magnets can pinch skin between poles or damage electronic devices
B. Magnets cure all illnesses instantly
C. Magnets are edible and safe to swallow
D. Magnets always start fires when left in sun
Correct answer: A ← Correct answer: A
Explanations:
A) Correct — powerful magnets can pinch and harm electronics like credit cards or pacemakers.
B/C/D) False and unsafe claims.