Grade 3 (age 8-9)

grade 3 Magnets and Magnetic Force

The magnet that holds a note on the fridge and the needle of a compass that helps you find your way both use the force of a magnet. The two ends of a magnet are the N pole and the S pole: different poles pull each other together, and matching poles push each other apart. A magnet pulls on things made of iron, and its force is strong up close and gets weaker quickly as you move away. In the first picture, widen or narrow the gap between two magnets and watch the arrows change length; in the second, move an iron paper clip away from a magnet and see the pull shrink.

The two poles of a magnet

Gap between the magnetsmedium

🧲 Magnet rules

①Each magnet has one N pole and one S pole at its two ends

②When different poles (N and S) face each other, they pull together

③When matching poles (N and N, S and S) face each other, they push apart

④The arrows show the force on each magnet, and they get longer as the gap narrows

The force around a magnet

Gap between magnet and clipmedium

💡 Distance and magnetic force

①Field lines trace the path from the N pole around to the S pole

②Near the poles the lines are packed close and farther out they spread apart, and where the lines are closer the force is stronger

③Move the iron clip away and the arrow showing its pull gets shorter fast

④Sprinkle iron filings on paper with a magnet underneath and this same line pattern appears

Summary

Magnetic poles

Different poles → pull together / Matching poles → push apart

N and S pull on each other, while two N poles or two S poles push each other away

Magnetic force and distance

Closer → stronger force / Farther → weaker force

Moving just a little farther away makes the force much smaller

🎯 Key points

①Even if you cut a magnet, each piece gets its own N pole and S pole

②Different poles pull together and matching poles push apart

③A magnet's force is strong up close and weakens quickly with distance

④A compass needle is a small magnet, so its N pole points north

⑤Magnets pull on iron, nickel, and cobalt, but not on plastic, wood, or aluminium

Examples and Unit Test

Example 1

What happens when you bring the N pole of one magnet close to the S pole of another?

The N pole and the S pole are different poles.

Different poles pull on each other, so the two magnets try to stick together.

▸ They pull together

Like the top pair in the first picture, when different poles face each other the arrows point toward each other.

Example 2

What happens when you face the N poles of two magnets toward each other and slowly bring them closer?

Two N poles are matching poles, so they push each other away.

A magnet's force is stronger up close, so the closer you bring them, the harder the push you feel in your hands.

▸ They push apart, and push harder the closer they get

Narrow the gap and the outward arrows on the bottom pair get longer.

Unit-test style

Which statement about magnets is correct?

①Matching poles pull each other together

②Different poles pull each other together

③The force gets stronger the farther you are from the magnet

④A magnet has only an N pole

⑤A magnet pulls on plastic

▸ ② Different poles pull each other together

Different poles, like N and S, pull each other together, while matching poles push apart.

Matching poles push apart (①), the force is stronger up close (③), a magnet always has both an N pole and an S pole (④), and plastic does not stick to a magnet (⑤).

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Last updated 2026-10-17