NCERT Solutions Curiosity Chapter 4 Activity 4.5: Let us experiment — Attraction and Repulsion between Magnets
Book page 68 Updated on2026-09-05
Q1.
Now bring one end of magnet B near the end of magnet A placed on the pencils. Make sure that the two magnets do not touch each other. Observe what happens.
Answer
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.
Top: the S pole of one magnet faces the N pole of the other, so the magnets pull together. Bottom: two S poles face each other, so the magnets push apart.
Why this proves action without contact: magnet A is on rollers and B never touches it, yet A moves. The push and the pull travel across the air gap. This is what makes magnetic force different from the everyday force of a hand shoving a box.
Q2.
Next, bring the other end of magnet B near the same end of magnet A (Fig. 4.8b). Does the magnet A on the pencils begin to move? Does it always move in the direction of the approaching magnet? What do these observations suggest?
Answer
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.
Poles facing each other
What magnet A does
Name of the effect
South of A ← North of B (Fig. 4.8a)
Rolls towards B
Attraction
South of A ← South of B (Fig. 4.8b)
Rolls away from B
Repulsion
What these observations suggest:
Unlike poles (North–South) attract each other. Like poles (North–North or South–South) repel each other.
Tip: Remember it as “opposites pull, sames push”. Only the flipping of magnet B changed between the two pictures — everything else stayed the same, so the poles must be the cause.
Q3.
Repeat the activity by using an iron bar in place of one of the magnets. What do you observe this time?
Answer
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.
Brought near the iron bar
Result
North pole of the magnet
Attraction
South pole of the magnet
Attraction
Either pole
Repulsion is never seen
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.
Why the iron bar never repels: the iron bar has no fixed poles. When a magnet comes near, poles are induced in the iron, and they always form the way round that produces a pull — the near face of the iron becomes the unlike pole. So whichever pole you offer, you get attraction.
Tip: This one idea answers three exercise questions of this chapter (Q5, Q6 and part of Q7). Repulsion is the sure test of a magnet.