Class 6 Science
Chapter 4 – Exploring Magnets (Complete Notes)
1. Introduction
Magnets have been used since ancient times. Sailors used a magnetic compass to find directions when stars were not visible.
There are two types of magnets:
- Natural magnets (Lodestone)
- Artificial magnets
Artificial magnets are used in:
- Pencil boxes
- Refrigerator doors
- Toys
- Electric motors
- Speakers
- Compasses
2. Types of Magnets
Natural Magnet
- Found naturally in nature.
- Example: Lodestone
Artificial Magnet
Made by humans.
Examples:
- Bar Magnet
- U-shaped Magnet
- Ring Magnet
- Disc Magnet
- Cylindrical Magnet
3. Magnetic Materials
Materials that are attracted by magnets.
Examples
- Iron
- Nickel
- Cobalt
- Steel (contains iron)
4. Non-Magnetic Materials
Materials that are not attracted by magnets.
Examples
- Wood
- Plastic
- Rubber
- Glass
- Paper
- Cloth
- Aluminium
- Copper
Difference Between Magnetic and Non-Magnetic Materials
| Magnetic Materials | Non-Magnetic Materials |
|---|---|
| Attracted by magnets | Not attracted by magnets |
| Iron, Nickel, Cobalt | Wood, Plastic, Glass |
5. Poles of a Magnet
Every magnet has two poles
- North Pole (N)
- South Pole (S)
Iron filings stick mostly at the poles because magnetic force is strongest there.
Important Facts
- Every magnet has two poles.
- Poles always exist in pairs.
- A single pole cannot exist.
6. Magnetic Compass
A magnetic compass contains a small magnetized needle.
Uses
- Finds directions
- Used by sailors
- Used during trekking
- Used in navigation
The red end generally indicates North.
7. Finding Directions
A freely suspended magnet always points towards
North – South Direction
Earth behaves like a giant magnet.
Therefore,
North Pole of magnet → North Direction
South Pole of magnet → South Direction
8. Earth's Magnet
The Earth itself behaves like a huge magnet.
Because of this,
- Compass always points North-South.
- Navigation becomes easy.
9. Making Your Own Compass
Materials
- Sewing needle
- Magnet
- Cork
- Bowl
- Water
Procedure
- Rub one pole of a magnet on the needle in one direction 30–40 times.
- Pass the needle through a cork.
- Float it on water.
- The needle will settle in the North-South direction.
10. Attraction and Repulsion
Unlike Poles
North – South
→ Attract each other
Like Poles
North – North
South – South
→ Repel each other
Golden Rule
Unlike poles attract. Like poles repel.
11. Identifying a Magnet
Only a magnet can
- Repel another magnet.
Iron can only be attracted.
Therefore,
Repulsion is the sure test of magnetism.
12. Magnetic Effect Through Materials
Magnetic force can pass through
- Wood
- Plastic
- Glass
- Cardboard
Therefore,
Magnets can attract objects without touching them.
13. Fun Uses of Magnets
Magnets are used in
- Maze games
- Magnetic garlands
- Magnetic toys
- Picking paper clips from water
- Matchbox cars
14. Care of Magnets
Do not
- Heat magnets
- Hammer magnets
- Drop magnets
- Keep near mobile phones
- Keep near remote controls
Store magnets
- In pairs
- Unlike poles together
- Soft iron keepers across the ends
- Wooden spacer in between
Important Definitions
Magnet
An object that attracts magnetic materials.
Magnetic Material
A material attracted by a magnet.
Non-Magnetic Material
A material not attracted by a magnet.
Magnetic Compass
An instrument used to find directions.
Pole
The end of a magnet where magnetic force is strongest.
Attraction
Force that pulls objects together.
Repulsion
Force that pushes objects apart.
Important Properties of Magnets
- Magnets attract iron, nickel and cobalt.
- Every magnet has two poles.
- Poles cannot exist separately.
- Freely suspended magnets point North-South.
- Like poles repel.
- Unlike poles attract.
- Magnetic force acts through non-magnetic materials.
- Magnetism is strongest at the poles.
Uses of Magnets
- Compass
- Refrigerator doors
- Electric motors
- Loudspeakers
- Earphones
- Cranes
- Toys
- Door locks
- Pencil boxes
Keywords
- Magnet
- Magnetic Materials
- Non-Magnetic Materials
- Pole
- North Pole
- South Pole
- Compass
- Attraction
- Repulsion
- Lodestone
- Bar Magnet
- Ring Magnet
- U-shaped Magnet
Important One-Mark Questions
- What is a magnet?
- What is lodestone?
- Name two magnetic materials.
- Name two non-magnetic materials.
- How many poles does a magnet have?
- Which pole is painted red?
- Which direction does a freely suspended magnet point?
- What is a magnetic compass?
- Which poles attract each other?
- Which poles repel each other?
Important Two-Mark Questions
- Define magnetic and non-magnetic materials.
- Explain attraction and repulsion.
- Why do iron filings collect at the poles?
- How is a compass useful?
- Why is Earth called a giant magnet?
Important Five-Mark Questions
- Explain the properties of magnets.
- Describe the construction and working of a magnetic compass.
- Explain how to make a simple compass.
- Explain attraction and repulsion with diagrams.
- Describe the uses and care of magnets.
Chapter Summary
- Magnets attract magnetic materials such as iron, nickel, and cobalt.
- Every magnet has two poles: North and South.
- A single magnetic pole cannot exist.
- A freely suspended magnet always aligns in the North–South direction.
- A magnetic compass uses this property to indicate directions.
- Unlike poles attract each other, while like poles repel each other.
- Magnetic force can pass through non-magnetic materials such as wood, plastic, glass, and cardboard.
- Magnets should be handled carefully and stored properly to retain their strength.