IMO Practice Test — Exploring Magnets
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
Object A attracts object B, but A does not repel B from any side. What can you conclude?
Both A and B are definitely magnets
A is a magnet and B may be a magnet or a piece of iron
Neither is a magnet
B is a magnet and A is iron
Explanation: Attraction alone is not proof; only repulsion confirms both are magnets.
Question 2 of 6
Iron filings are sprinkled on a bar magnet. The pattern shows fewest filings at the middle because there:
The magnet is broken
The magnetic force is weakest
The iron is heavier
There are extra poles
Explanation: The force is weakest in the middle and strongest at the poles.
Question 3 of 6
A magnet is cut into three pieces. The total number of poles among the three pieces is:
2
3
6
1
Explanation: Each piece is a complete magnet with 2 poles, so 3 pieces have 6 poles.
Question 4 of 6
Why must a bar magnet not be hammered or dropped repeatedly?
It will become heavier
It may lose its magnetism
It will gain extra poles
It will change colour
Explanation: Rough treatment disturbs the magnet and weakens or destroys its magnetism.
Question 5 of 6
A floating magnetised needle on cork points north-south. If you bring the north pole of a bar magnet near its north-seeking end, the needle end will:
Move away (repelled)
Move towards it (attracted)
Not move at all
Spin continuously
Explanation: Two north poles are like poles, so they repel and the needle end moves away.
Question 6 of 6
Which property of a freely suspended magnet makes the compass possible?
It always points north-south
It is heavy
It is shiny
It attracts copper
Explanation: A free magnet aligns north-south, which lets a compass show direction.