Question

the images below show four pairs of magnets. the magnets in different pairs do not affect each other. all the magnets shown are made of the same material, but some of them are different sizes.
think about the magnetic force between the magnets in each pair. select the pair with the magnetic force of greatest magnitude.
pair 1
pair 2
0.9 cm
2.25 cm
pair 3
pair 4
0.9 cm
2.25 cm

Explanation:

Step1: Recall magnetic force factors

Magnetic force magnitude depends on magnet size (mass/volume, since same material, size relates to strength) and distance. Larger magnets (same material) have stronger force. Smaller distance also increases force.

Step2: Analyze each pair

• Pair 1: Different sizes, distance 0.9 cm. But smaller magnet weakens force.
• Pair 2: Different sizes, distance 2.25 cm (larger distance than 0.9 cm), and different sizes (small and large, but repelling? Wait, poles: Pair 2 has N-S (small) and N-S (large)? Wait, no: Pair 2 left is N-S (small), right is N-S (large). Wait, poles: left magnet N (blue) and S (green), right magnet N (blue) and S (green). So like poles? Wait, no: left magnet: N (blue) on left, S (green) on right. Right magnet: N (blue) on left, S (green) on right. So left magnet's S (right) and right magnet's N (left) – wait, no, positions: Pair 2: left magnet (small) has N (blue) left, S (green) right. Right magnet (large) has N (blue) left, S (green) right. So distance between them: 2.25 cm. The poles facing: left magnet's right (S) and right magnet's left (N) – attractive? Wait, but sizes: small and large. But distance is 2.25 cm.

• Pair 3: Same size (both large? Wait, Pair 3: both magnets are same size (large), distance 0.9 cm. Poles: both have N (blue) left, S (green) right. So facing poles: left magnet's right (S) and right magnet's left (N) – attractive? Wait, no: left magnet: N (blue) left, S (green) right. Right magnet: N (blue) left, S (green) right. So left magnet's S (right) and right magnet's N (left) – attractive. And both are large magnets (same size, so same strength), distance 0.9 cm (small distance).

• Pair 4: Same size (both large), distance 2.25 cm. Poles: both have S (green) left, N (blue) right. So facing poles: left magnet's right (N) and right magnet's left (S) – attractive. But distance is 2.25 cm (larger than 0.9 cm).

Step3: Compare Pair 3 and others

Pair 3: same large size (so strong magnets), distance 0.9 cm (small distance). Pair 4: same large size, but distance 2.25 cm (larger, so force weaker than Pair 3). Pair 1: different sizes (small and large), distance 0.9 cm, but smaller magnet reduces force. Pair 2: different sizes, larger distance, and different sizes (small and large, repelling? Wait, no, poles: Pair 2 left is N-S (small), right is N-S (large). Wait, left magnet: N (blue) left, S (green) right. Right magnet: N (blue) left, S (green) right. So left magnet's S (right) and right magnet's N (left) – attractive, but different sizes (small and large) and distance 2.25 cm.

So Pair 3 has same large size (maximizing magnet strength) and smallest distance (0.9 cm), so magnetic force magnitude is greatest.

Answer:

Pair 3