Question
A student picks up several objects from around the house — an iron nail, a plastic ruler, a copper coin, a wooden pencil, and a nickel coin. Which of these will be attracted to a bar magnet? How do we test this?
Solution — Step by Step
Hold a bar magnet close to each object — do not touch yet. If the object gets pulled toward the magnet, it is magnetic. If nothing happens, it is non-magnetic.
The key is bringing the magnet near, not pressing it against the object. A weak attraction is still attraction.
Bring the magnet near the iron nail. The nail jumps toward the magnet immediately.
Iron is magnetic — this is the classic example. Iron, along with nickel and cobalt, forms the group of ferromagnetic materials.
Bring the magnet near the copper coin. Nothing happens — the coin stays still.
Copper looks shiny and metal-like, so students assume it must be magnetic. But copper is non-magnetic. Being a metal does not automatically mean being magnetic.
Neither the plastic ruler nor the wooden pencil shows any attraction.
Non-metals like plastic and wood are almost always non-magnetic. These are safe, predictable results.
Indian coins are mostly steel (iron alloy), so they will be attracted. A pure nickel object would also be attracted since nickel is ferromagnetic.
Result: Iron nail ✓ and nickel (or steel coin) ✓ are magnetic. Plastic ruler ✗, wooden pencil ✗, copper coin ✗ are non-magnetic.
Why This Works
Only three naturally occurring metals are strongly magnetic at room temperature — iron, nickel, and cobalt. These materials have a special internal structure where tiny regions called magnetic domains line up when a magnet is brought near them. That alignment creates attraction.
Most other metals — copper, aluminium, gold, silver — do not have this domain structure, so a magnet has no effect on them. Non-metals like wood, plastic, rubber, and glass are completely non-magnetic.
A quick memory trick for the three magnetic metals: Fe-Ni-Co (Iron-Nickel-Cobalt). Say it as “Fe-Ni-Co” — sounds like “Pheni ko” which is easy to remember!
Alternative Method
Instead of a bar magnet, we can use a magnetic compass to test materials. Bring the object close to the compass needle. If the needle deflects (moves), the object is magnetic. If it stays pointing north, the object is non-magnetic.
This works because the compass needle is itself a small magnet — any nearby magnetic material disturbs it. This method is more sensitive and can detect weak magnetism that might be hard to feel by hand.
Common Mistake
Assuming all metals are magnetic. This is the most common error in Class 6 and even in Class 10 revision. Copper, aluminium, silver, gold, and zinc are all metals — but none of them are attracted to a magnet. The magnetic property depends on the type of metal, not the fact that it is a metal. In board exams, questions often give a copper or aluminium object and ask if it is magnetic — the answer is always no.