Introduction — What are magnets?
Magnets are objects that attract certain types of materials such as iron, nickel and cobalt. A magnet has two ends called poles — the north pole and the south pole. When two magnets are brought close to each other, the poles interact: like poles repel and unlike poles attract. Magnets can be found in different shapes such as bar magnets, horse-shoe magnets and ring magnets. In this chapter you will explore what magnets do, how they affect nearby objects, how to show magnetic fields and how magnets are used in everyday life.
Key concepts and definitions
An object that attracts magnetic materials.
Ends of a magnet where magnetic force is strongest.
The area around a magnet where its force is felt.
Material attracted by a magnet (e.g., iron).
Understanding these words helps you read and answer questions in exams. The magnetic field, though invisible, is a key idea — it explains why a magnet can attract an iron nail from a small distance without touching it.
Poles and magnetic fields
Every magnet has two poles. We call one the North pole and the other the South pole. The strongest magnetic effects are found at the poles. If you bring two north poles close together, they push away from each other. Two south poles do the same. A north pole and a south pole attract each other.
Magnetic field lines (or simply field lines) are used to show the direction of the magnetic force. Field lines go from the north pole to the south pole outside the magnet. The closer the lines are, the stronger the magnetic field in that region. Field lines never cross each other and form continuous curves.
Magnetic and non‑magnetic materials
A magnetic material is attracted to a magnet. The common magnetic materials are iron, steel (an alloy of iron), nickel and cobalt. Non-magnetic materials such as wood, plastic, glass and cloth are not attracted by magnets. In the classroom you can test many small items using a bar magnet — paper clips, pins and nails (magnetic); coins, coins from some countries, and plastic objects (usually non-magnetic).
| Magnetic materials | Non-magnetic materials |
|---|---|
| Iron nail, paper clip, steel pin | Wooden pencil, plastic ruler, rubber eraser |
| Some coins (depending on metal), compass needle | Glass, cotton cloth |
Hands-on experiments (step-by-step)
Experiment 1 — Which objects are magnetic?
- Materials: A bar magnet, a tray of small objects (paper clips, plastic beads, wooden pieces, coins, pins).
- Method: Bring the magnet near each object and see whether it is attracted.
- Observation: Write down which objects stick to the magnet and which don't.
- Conclusion: Objects made of iron or steel will be attracted — these are magnetic. Objects like plastic and wood will not be attracted — non‑magnetic.
Experiment 2 — Showing magnetic field lines
- Materials: A bar magnet (or two), a piece of white paper, iron filings or small iron filings substitute (some teachers use tiny iron dust).
- Method: Place the magnet beneath the paper and gently sprinkle the iron filings on top. Tap the paper gently to let the filings settle.
- Observation: The filings line up along curves showing the magnetic field. The pattern shows field lines spreading out from the north pole and entering the south pole.
- Safety note: Do not inhale iron filings. Keep them away from eyes and electronics like phones. Use a tray to contain the mess.
Experiment 3 — Repulsion and attraction
- Materials: Two bar magnets or two small magnets.
- Method: Hold one magnet still and bring the other magnet close. Try different orientations (N to N, S to S, N to S).
- Observation: You will feel a push when like poles face each other and a pull when opposite poles are brought close.
- Conclusion: This shows how poles interact — a simple and important idea that explains many uses of magnets.
Temporary and permanent magnets
Permanent magnets keep their magnetic properties for a long time. A piece of magnetised steel is a permanent magnet. A temporary magnet is a material that behaves like a magnet when it is near a permanent magnet but loses magnetism when taken away. For example, a paper clip can become temporarily magnetised when it is touching a strong magnet. Many everyday devices use temporary magnetism to switch circuits or hold things momentarily.
Use of magnets in everyday life & technology
Magnets are used in many places around us. Here are some common applications:
- Compass: A small magnetised needle aligns with Earth’s magnetic field and points towards the north-south direction. This helps in navigation.
- Electric motors: Magnets interact with electric currents to produce rotation. Motors in fans, toys and appliances depend on this principle.
- Speakers and earphones: They use magnets and coils to convert electrical signals into sound.
- Magnetic separators: Used in recycling and industry to separate metals from other materials.
- Everyday uses: Refrigerator magnets, magnetic clasps, magnetic latches and magnetic name tags.
Safety and care of magnets
- Keep strong magnets away from electronic devices, credit cards, and magnetic storage devices.
- Do not swallow small magnets. If swallowed, they can be dangerous; inform an adult and seek medical help.
- Store magnets apart or with a keeper (a soft iron bar) to protect them from damage and loss of magnetism.
Study tips & how to answer CBSE questions
- Learn the key definitions by heart: magnet, pole, magnetic field, magnetic material.
- Practice drawing a magnet and simple magnetic field lines — label north and south poles clearly.
- Remember the rule: like poles repel, unlike poles attract. Give one example in answers.
- Write short steps for experiments (materials, method, observation, conclusion). CBSE often asks for such steps in the exam.
- Connect applications to principles: for example, how a compass needle aligns with Earth’s magnetic field.
Sample short & long questions (with brief answers)
Q1. What is a magnet? Give two examples. (2 marks)
A. A magnet is an object that attracts magnetic materials like iron. Examples: bar magnet and horse-shoe magnet.
Q2. Explain with an experiment how you would show that the region around a magnet is a magnetic field. (4 marks)
A. Place a bar magnet beneath a sheet of paper and sprinkle iron filings on the paper. Tap gently. The filings form lines that curve from the north pole to the south pole of the magnet. This pattern shows the magnetic field around the magnet.
Q3. State two uses of magnets in daily life. (2 marks)
A. (i) Magnetic compass for direction; (ii) motors in electric fans and toys.
Q4. Why are some materials not attracted by a magnet? Give two examples. (3 marks)
A. A material is not attracted by a magnet if it does not contain iron, nickel or cobalt atoms arranged to react to magnetic fields. Examples: plastic and wood.
Revision checklist (quick)
- Know definitions and examples of magnets.
- Be able to list magnetic vs non-magnetic materials.
- Practice two short experiments: attraction test; iron filings for field lines.
- Recall applications and safety rules.
- Practice simple diagrams and lab steps for exam answers.