NCERT Solutions for Class 6 Science Chapter 4 Exploring Magnets (PDF) – 2027

Yes. Magnets stick only to objects made of certain materials — mainly iron, and also nickel and cobalt (and steel, which is mostly iron). An iron nail or a steel U-clip sticks to a magnet; a wooden pencil or a rubber eraser does not.

Write the prediction column before you test. A sample completed Table 4.1, using objects from Fig. 4.3 (your own objects may differ):

No, not for all objects. The usual wrong guess is a shiny metal such as the copper electric wire — it looks as if it should stick, but it does not.

Materials that stuck: iron and steel — the screw, the paper clip, the iron key and the blades of the scissors.

Conclusion:

The non-magnetic materials in Table 4.1 (completed in the card above) were wood (pencil), rubber (eraser), copper and plastic (electric wire), glass (tumbler), wax (candle) and cotton (cloth). None of them was attracted by the magnet.

No. The pull of a magnet is not the same everywhere along it. It is strongest at the two ends and weakest in the middle.

Observation: the iron filings do not stick uniformly all over the magnet. Most of them stick in two thick bunches at the two ends of the bar magnet, and only a few stick near the middle. So the filings stick much more at the ends — the poles of the magnet.

Yes — the result is the same for every shape. Whatever the shape of the magnet, most of the iron filings collect at its poles.

No. A magnet with a single pole cannot exist. North and South poles always occur in pairs.

Test it: take a bar magnet marked N and S, and break it in two.

Yes. No matter how many times you spin the freely suspended bar magnet, it always settles back along the same line that you had marked on the ground.

The line is the north-south line. A freely suspended magnet always rests along the north-south direction.

How to check it without a compass: use the Sun. The Sun rises roughly in the east and sets roughly in the west. Stand in the morning with your right arm pointing towards the rising Sun; then you face north and your back is to the south. Compare this with the line you marked — the two agree.

Observation: the iron bar stops wherever it happens to stop. It may rest east-west, or slanting, or north-south — and a different direction each time.

No, it does not always rest along the north-south direction.

Rub an iron sewing needle 30 to 40 times with one pole of a bar magnet, always in the same direction, so that the needle becomes a magnet. Push it horizontally through a cork and float the cork in a bowl of water. The needle comes to rest along the north-south direction — this is our own magnetic compass (Activity 4.4).

Yes. However many times you spin the cork, the needle swings a little and then settles with the same end pointing north and the other end pointing south, every single time.

It depends entirely on which poles face each other — and there are only two possible results.

Observation: magnet A rolls towards magnet B, even though the two never touch. In Fig. 4.8a the South pole of magnet A faces the North pole of magnet B — unlike poles — so they attract.

Yes, magnet A begins to move — but this time it rolls away from magnet B.

No, it does not always move towards the approaching magnet. The direction of the movement is decided by the poles that face each other.

What these observations suggest:

Observation: the iron bar is attracted by both ends of the magnet. Bring the North pole near it — it is pulled. Bring the South pole near it — it is pulled again. It is never pushed away.

Conclusion: a magnet can be identified by its property of repulsion, not by attraction. Attraction alone is not proof, because a plain piece of iron also attracts a magnet.

Yes. The compass needle is a small, freely rotating magnet, so it obeys exactly the same rules as a bar magnet — its North pole is repelled by another North pole and attracted by a South pole.

Yes, the needle deflects. The North pole of the needle moves away from the approaching North pole of the bar magnet — the needle swings round until its North end points elsewhere.

Yes — the deflection is now in the opposite sense. The North pole of the compass needle moves closer to the approaching South pole of the bar magnet (Fig. 4.9b).

No, it will not. The compass needle deflects by very nearly the same amount as before. The wood does not block the magnetic effect.

There is no appreciable effect. Record it like this:

The result is the same for all four. Completed Table 4.2:

Conclusion:

Yes. Hold a bar magnet and touch steel pins to its poles one after another. A pin sticks to the pole, the next pin sticks to that pin, and so on, so a chain of pins hangs from each pole. When the two chains are brought together at their lower ends, they join and make a garland hanging from the magnet (Fig. 4.11).

Yes. Hold the magnet under the cardboard tray, right below a steel ball, and slide it slowly. The ball follows the magnet through the maze and can be walked all the way to the exit — without ever touching it.

Yes. Hold the magnet outside the glass, against its wall, level with the clip. The clip is attracted through the glass and the water and clings to the inside wall. Now slide the magnet slowly up the outside of the glass; the clip climbs up with it and can be taken out at the rim. Neither the fingers nor the magnet get wet.

In Fig. 4.14 the two matchbox cars carry magnets with like poles facing each other, so they will run away from each other — they repel.

Use one rule only — like poles repel, unlike poles attract.

Answer: option (i) — Position A: 10, Position B: 2, Position C: 10.

In Fig. 4.15, A and C are the two ends of the bar magnet (the poles) and B is the middle.

She should use the test of repulsion. She takes the bars two at a time (1 and 2, 1 and 3, 2 and 3) and brings each end of one bar near each end of the other.

1. Place the unmarked magnet on the table, or on round pencils so that it can move easily.
2. Bring the North pole of the marked magnet slowly near one end of the unmarked magnet.
3. If that end is pushed away (repelled), it is the North pole of the unmarked magnet.
4. If that end is pulled (attracted), it is the South pole.
5. The other end is then the opposite pole. Mark both ends with a marker pen.

Tie a thread to the middle of the bar magnet and hang it freely, away from iron objects. Let it come to rest. It rests along the north-south direction, and the end that points towards the north is its North pole. (To know which side is north: face the rising Sun, which is roughly east; north is then on your left.)

Yes. The Earth’s magnet is turned the other way round from the geographic directions:

Magnetise the tip of the screwdriver. Then each steel screw clings to the tip instead of dropping into the machine.

To do this, stroke the steel shaft of the screwdriver 30 to 40 times with one pole of a bar magnet, from the handle end to the tip, always in the same direction (as the needle was magnetised in Activity 4.4). The magnetised tip then holds the steel screws.

Reason: the faces of X and Y that face each other are like poles (both North or both South). Like poles repel, so magnet X is pushed up and stays floating above Y.

Way to bring them in contact: take X off the rod, turn it upside down and put it back on the rod. Now unlike poles face each other, so X is attracted and moves down by itself until it touches Y.

Answer: 1 = N, 2 = S, 3 = N, 4 = S, 5 = N (given), 6 = S.

Touching ends that stay together must be unlike poles, and each magnet has one N and one S.

(your own numbers will differ): the U-shaped magnet lifted the most pins and the small bar magnet the fewest.

Why different magnets pick up different numbers of pins: magnets differ in strength — because of the material they are made of, their size, their shape (the two poles of a U-shaped magnet pull on the heap together) and how they have been kept (dropping, heating or hammering weakens a magnet).

How the frog hops: the ring magnets on the scale are fixed with their poles alternating — N, S, N, S …. As the frog’s magnet slides over them, it is repelled by a like pole (the frog jumps up) and then attracted by the next, unlike pole (it comes down). So the frog appears to hop along the scale.

What a Maglev train is: “Maglev” is short for magnetic levitation. The train does not roll on wheels — it floats a little above the guideway and is pushed forward by magnets.

A simple model: fix a row of magnets along a wooden channel with the same pole facing up, and glue magnets under a light cardboard “train” with the same pole facing down. Like poles face each other, so the train floats above the channel and glides along when pushed gently.

Because the shape decides where the poles are — and different jobs need the poles in different places.

Uses of magnets in medicine (sample findings):