Magnetism is an invisible force of attraction (pull) or repulsion (push) between certain types of materials. It is created by the alignment of electrons within an object, which forms a magnetic field made up of invisible lines of force.

1. Permanent Magnets & Magnetic Poles

Permanent magnets are objects designed to keep their magnetic properties for a very long time.

• Magnetic Materials: Magnets are attracted to metals containing iron. Because steel contains iron, magnets stick to everyday items like paperclips, nails, screws, and safety pins.

• Magnetic Poles: Every magnet has a North Pole and a South Pole.

  • Unlike poles attract: North + South pull together.

  • Like poles repel: North + North or South + South push apart.

• Earth as a Magnet: The Earth has an iron core that acts as a giant permanent magnet. This creates a magnetic field that allows compasses to point toward Earth's magnetic north pole for navigation.

2. Electromagnets: Temporary & Adjustable Magnets

An electromagnet is a temporary magnet created by running an electric current through a wire wrapped around a metal core (such as a copper wire coiled around a steel nail connected to a battery).

[ Battery ] ──(Wire)──> [ Coiled Wire around Iron Nail ] ──> Creates Magnetic Field!

• On/Off Control: Unlike permanent magnets, electromagnets can be turned on (electric current flowing) or off (electric current stopped).

• How to Make an Electromagnet Stronger:

  1. Add more coils of wire around the metal core.

  2. Increase the power source (using a bigger battery or additional batteries).

• Everyday Uses: Found in household items like doorbells, audio speakers, and scrap metal cranes.

3. Magnetic Fields Pass Through Materials

A magnet's force field extends into the space around it. The strength of a magnetic field can easily pass through thin non-magnetic barriers such as paper, wood, glass, plastic, or water (for example, sliding a magnet underneath a piece of paper to move a paperclip on top).

Quick Comparison: Permanent vs. Temporary Magnets

Feature Permanent Magnets Electromagnets (Temporary)

Source of Magnetism Aligned electrons in iron/metals Electric current flowing through wire

Can turn on/off? No, always magnetic Yes, controlled by a circuit

Adjustable strength? No, strength stays fixed Yes, by changing batteries or wire coils

Everyday Examples Refrigerator magnets, navigation compasses Doorbells, music speakers, electric motors