Chapter 6 — Magnetism

What is a magnet?

A magnet is any object that shows a special force called magnetic force. This force can pull certain metals towards the magnet even without touching them. Children commonly see magnets as bar-shaped pieces of metal, horseshoe shapes, rings or small refrigerator magnets. Magnets are used to attract small metallic objects like paper clips, pins and nails. There are naturally occurring magnets found in rocks, and there are man-made magnets made in factories.

A magnet always affects a space around it — we call this area the magnetic field. Within this field the magnet can pull or push other magnets and certain metals. Not everything is affected: materials such as wood, plastic and glass usually feel no effect. The simplest way to understand a magnet is by trying easy experiments: bring a magnet near different household objects and notice which move and which do not. This hands-on observation builds the first clear idea about magnets for young learners.

Teachers should encourage students to describe what they feel and see, for example the way a paper clip jumps to a magnet. Use everyday language: magnets "pull" some metals and do not affect others. Make sure students know that magnets can vary in strength — some pick up many objects while others are weak and lift only one. These simple observations form the base for later learning about poles, fields and electromagnets.

Magnetic and non-magnetic materials

Materials respond differently to a magnet. Magnetic materials are pulled towards a magnet. Most commonly these are iron, steel (an iron alloy), nickel and cobalt. Non-magnetic materials are not attracted; examples include wood, plastic, glass, rubber, copper and aluminium. Some metals that look shiny may still be non-magnetic if they are not made from magnetic elements.

To identify which objects are magnetic, perform a simple test: bring a magnet near the object and watch if the object moves. Record the result in a table with two columns — Magnetic and Non-magnetic — and place each tested item under the proper column. This activity teaches classification and encourages careful observation. It also highlights that coatings or paint do not always show the true nature of the core material; a painted iron nail is still magnetic even when paint covers it.

Some materials behave like temporary magnets when placed near a strong magnet. For instance, an iron nail becomes magnetic while close to a bar magnet and can pick up small pins, but it loses most of that magnetism when the magnet is removed. Heating or hammering a magnet can change its magnetic properties, often reducing them. Students should learn to test many different objects so they notice patterns: objects made of iron or steel are usually magnetic, while materials like wood, plastic and glass are not. This practical approach builds a strong foundation for understanding magnetic behaviour.

Magnetic poles, attraction and repulsion

Every magnet has two ends called poles: one is the north pole and the other is the south pole. If a bar magnet is allowed to hang freely, the pole that points towards the Earth's geographic north is called the north-seeking pole (or simply north pole) of that magnet. The other end is the south pole. Poles always come in pairs; even if you cut a magnet into two pieces, each piece will have its own north and south poles.

Poles determine how magnets interact. If opposite poles (north and south) of two magnets are brought close, they attract or pull towards each other. If like poles (north-north or south-south) are brought close, they repel or push away. Students can feel this by bringing two small magnets together slowly: one arrangement will snap them together while the other will push them apart. The strength of attraction or repulsion changes with distance — it is stronger when the magnets are nearer and weaker when farther apart.

Poles are also where the magnetic field is strongest. When drawing magnets, always mark the ends as N and S. Simple classroom activities using string to suspend a magnet, or using pairs of magnets, let pupils see attraction and repulsion clearly. Encourage them to describe their observations in words: "opposite poles attract" and "like poles repel". These short rules help students predict what will happen in many simple situations with magnets.

Magnetic field: idea, field lines and different shapes

A magnetic field is the area around a magnet where its force acts. The field is invisible, but we can show its shape by using iron filings or a compass. Field lines help us picture the field: they are drawn as lines that show the path a tiny north pole would follow. Outside a magnet the lines leave the north pole and enter the south pole. Field lines are closer together where the field is stronger and spread out where it is weaker. They never cross each other.

Different magnet shapes make different field patterns. A bar magnet has wide curved lines linking north and south across its ends. A horseshoe magnet bends the magnet so the two poles are near each other; the field between them becomes short and concentrated, making that region very strong. A ring magnet shows lines passing through the hole and returning outside; this pattern is different from a straight bar. When two magnets are placed near each other the fields combine: opposite poles cause field lines to join smoothly and create a strong path, while like poles cause lines to push apart and may form neutral regions where a small compass needle does not point clearly.

In class, place a magnet under a sheet of paper and sprinkle iron filings on top. Tap the paper gently so the filings settle along the field lines — the resulting pattern makes the invisible field visible. Use a compass to trace directions at many points and join the marks to draw field lines. Observing how field patterns change with magnet shape or with two magnets together helps students deepen their understanding of magnetic fields and why pole arrangement matters.

Using a compass and the Earth as a magnet

A compass has a small magnetised needle that can turn freely. The needle aligns with the local magnetic field and therefore points roughly towards the Earth's geographic north. We call the end that points north the north-seeking end. When using a compass, hold it level and keep it away from other magnets or large metal objects so the needle can show the true direction. Compasses are useful for finding directions and for tracing magnetic field lines in experiments.

The reason a compass points roughly north is that the Earth itself behaves like a very large magnet. The Earth has a magnetic field whose poles are not exactly at the geographic poles but are close enough for simple navigation. Because of this field a small suspended magnet or a compass needle aligns with the Earth's field and indicates a north-south line. Teach students to try a simple activity: suspend a bar magnet with a thread and see it turn to align north-south. Then compare with a compass reading for practice.

When mapping a magnet's field, place a compass at several positions around the magnet, mark the direction of the needle at each point and join the marks smoothly to form field lines. This shows the local direction of the magnetic field. Explain that compasses can be disturbed by nearby metal objects or other magnets; this is why mariners and hikers keep electronics and strong magnets away from their compass. These activities help students link classroom experiments to real-life navigation and to understand the idea of the Earth as a magnet in simple terms.

Permanent and temporary magnets

Magnets are often described as permanent or temporary. A permanent magnet keeps most of its magnetism for a long time without needing any external influence. Fridge magnets, compass needles and many manufactured bar magnets are examples. Permanent magnets are useful when a steady magnetic effect is needed. Temporary magnets, on the other hand, act like magnets only while they are in a magnetic field or have a magnetic influence applied. A piece of iron near a strong magnet becomes magnetic but returns to non-magnetic behaviour when the strong magnet is removed.

Students can make a simple permanent magnet by stroking a steel needle or small bar in one direction repeatedly with a strong magnet. This process aligns small regions inside the steel so that they act together as a magnet. Temporary magnetism is easily shown by bringing an iron nail near a bar magnet and using the nail to pick up pins only while it is close to the bar magnet. Explain that heating, hammering or dropping a magnet can disturb the order inside it and reduce its strength — this is why some magnets lose power over time or when mistreated.

Discuss practical examples: iron filings near a magnet stick only where the field is present; a crane using an electromagnet can lift scrap metal only while current flows. This comparison helps students see why some applications need permanent magnets while others need temporary, controllable magnetism. Encourage simple tests in class to make and compare small permanent and temporary magnets and to record observations about how long they remain magnetic.

Making a simple electromagnet

An electromagnet is created when electric current flows through a coil of wire, producing a magnetic field. A basic classroom electromagnet can be made by winding insulated copper wire around an iron nail and connecting the wire ends to a low-voltage cell. While the cell supplies current, the nail becomes magnetic and can pick up small iron objects like paper clips. When the connection is opened and current stops, the nail loses most of its magnetism and the paper clips fall away. This clear on-off behaviour shows how electricity and magnetism are linked.

To make an electromagnet safely: use a single dry cell or small battery, insulated copper wire, and a clean iron nail. Wind many turns of the wire neatly around the nail; more turns usually give a stronger magnet. Strip the wire ends carefully and make secure connections to the battery terminals. Use the electromagnet only for short periods to avoid heating the battery. Never use mains electricity in classroom demonstrations and always perform this activity under adult supervision. Keep the setup away from electronic devices and credit cards which can be affected by magnets.

Encourage students to test how the number of turns or the number of batteries affects the lifting power, and to record how many paper clips are lifted in each case. This experimental approach teaches that the strength of an electromagnet depends on current and coil turns. Discuss real-life uses such as scrapyard cranes that switch magnetism on and off, and electric bells where an electromagnet attracts and releases a hammer repeatedly to make sound. These examples link the simple classroom device to larger practical machines.

Care and safety with magnets

Working with magnets is simple but needs attention to safety. Small strong magnets can pinch skin if two are allowed to snap together quickly. Keep magnets away from electronic devices such as mobile phones, watches, credit cards and devices with magnetic storage because strong magnets can damage stored information or change device behaviour. When using iron filings, do the activity over a tray and wear eye protection if needed; avoid letting filings come near the eyes and clean them up carefully.

Never put small magnets in the mouth or swallow them. If more than one small magnet is swallowed, they can attract inside the body and cause serious injury; this is a medical emergency. When making electromagnets use only low-voltage cells and brief experiments so batteries do not heat up. Ensure wire ends are insulated except where you need a connection and that no mains supply is used for these demonstrations. Also store magnets in a labelled box and keep them out of reach of very young children.

Teach students safe habits: carry magnets apart, do experiments on stable tables, and ask for help if something goes wrong. Explain that striking or heating permanent magnets can reduce their strength; this is why magnets should be handled gently. By following these rules students can enjoy learning about magnetism while avoiding harm to themselves and to sensitive equipment.

Uses of magnets in daily life

Magnets appear in many everyday objects and machines. Fridge magnets hold notes and pictures on refrigerator doors. Magnetic latches and closures are used in bags and cupboards to keep doors shut without a visible lock. Electric bells use electromagnets; when the coil is energized the magnet pulls a hammer which strikes the bell and produces sound. Loudspeakers use magnets and coils together to change electrical signals into movements that make sound. In recycling and scrapyards, large electromagnets lift and move iron and steel objects easily.

Magnets are also used in toys to connect parts or make moving pieces, and small magnets appear in some home appliances. In the classroom and in laboratories magnets are used for experiments and demonstrations. Although many electronic devices contain magnets inside them, strong external magnets can damage certain types of data storage or delicate sensors. In advanced technology, magnets are essential in motors, generators and medical imaging machines — these are specialised applications handled by experts, but the basic idea comes from the same magnetic behaviour studied here.

Ask students to find examples at home and school of magnet use and explain briefly how each uses magnetism. This activity helps children connect simple classroom ideas to the world around them and understand the wide range of tasks magnets can perform, from holding a note to lifting heavy metal objects in industry.

Simple experiments to observe magnetism

Hands-on activities make magnetism clear and memorable. Simple safe experiments include: 1) Testing objects around the classroom to decide which are magnetic and which are not, recording results in a table. 2) Sprinkling iron filings on paper placed above a magnet to reveal field lines; tap gently so filings settle along the lines. 3) Using a compass at several points around a magnet to trace directions and join marks to draw field lines. 4) Making a small electromagnet with insulated wire, an iron nail and a dry cell to show magnetism produced by electric current.

Each experiment shows a different aspect of magnetism: attraction, field patterns, direction and the link with electricity. Encourage students to write short observations and explain why they think the result happened. For example, note that filings gather more near poles where the field is strong; or that the electromagnet only works when the battery is connected. Let groups present findings so everyone sees different results and methods.

Safety must be emphasised: do filings experiments on trays and keep them away from eyes; keep magnets away from electronic devices and personal items; use batteries briefly and under supervision. After experiments, ask pupils to draw neat diagrams showing setups and results; this helps to connect practical work to the written knowledge and prepares students for tests and class discussions.

Magnets and electricity: simple link

Electricity and magnetism are connected. A flow of electric charge called current produces a magnetic field around the conductor. In Class 6 we learn this link through simple demonstrations rather than mathematics. For instance, when current flows in a straight wire, a small compass placed nearby will show a deflection because the wires magnetic field affects the compass needle. In a coil of wire the fields of many turns combine to form a stronger effect similar to a bar magnet; this is the idea behind an electromagnet.

Simple demonstrations include placing a compass near a single wire and closing and opening a circuit to see the needle move only while current flows. Building an electromagnet with a nail and wire shows that switching the battery on makes the nail magnetic and switching it off removes the effect. Explain in simple words that moving charges (current) create magnetism; the more current or the more turns in a coil, the stronger the magnetic effect usually becomes.

This idea prepares students for later classes where they learn specific rules and formulas. For now, focus on safe, supervised experiments that let learners see cause and effect: current flows — magnetic effect appears; current stops — effect disappears. Encourage recording results and explaining observations in sentences to strengthen understanding of this important link between electricity and magnetism.

Review and revision activities

To complete the unit, use short revision tasks that combine practical work, drawing and short written answers. Ask students to label parts of a magnet, list five magnetic and five non-magnetic items from home, and draw field lines for a bar and a horseshoe magnet. Group activities can include performing a simple experiment and presenting the result: for example, each group maps a magnetic field using a compass and explains what they found. Oral question-and-answer rounds help quick recall of rules such as "opposite poles attract" and "like poles repel".

Provide a few structured worksheets: one with pictures to label poles and field lines, another with a table for testing objects, and a short worksheet that asks pupils to describe how an electromagnet is made. Encourage neat diagrams with clear labels and arrows because visual clarity helps retain concepts. For homework ask students to find five uses of magnets at home and write one sentence about each use linking it to magnetic properties.

Finally, include a small practical test: ask each student to show how to test whether an object is magnetic and to trace a field line with a compass at three points. This confirms they can both observe and explain. Revision in these varied forms — doing, drawing and explaining — ensures students remember the main ideas and are ready for further study in higher classes.