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 smallest magnitude.

Explanation:

Step1: Recall magnetic - force factors

The magnetic force between two magnets depends on their pole - strength and the distance between them. For magnets of the same material, larger magnets have greater pole - strength. The force is inversely proportional to the square of the distance between the magnets.

Step2: Analyze each pair

Pair 1 and Pair 3 have the same distance (1.3 cm), but Pair 3 has smaller magnets, so the force in Pair 3 is smaller than in Pair 1. Pair 2 and Pair 4 have the same distance (3 cm), and Pair 4 has smaller magnets. Also, comparing the smaller - magnet pairs (Pair 3 and Pair 4), since 3 cm > 1.3 cm, the magnetic force in Pair 4 is the smallest.

Answer:

Pair 4