Difficulty: Easy
Correct Answer: Incorrect
Explanation:
Introduction / Context:
Magnetostatics principles mirror electric charges: like poles repel, unlike poles attract. This rule underlies basic applications from magnetic separation to motor stator–rotor interactions and the design of magnetic couplings.
Given Data / Assumptions:
Concept / Approach:
Magnetic field lines emerge externally from the north pole and enter the south pole. Like poles produce opposing field patterns when brought together, raising magnetic reluctance and resulting in a repulsive force. Attraction occurs when a north is near a south, because field lines can connect directly, lowering energy in the field configuration.
Step-by-Step Solution:
Verification / Alternative check:
Hands-on test with two bar magnets shows clear repulsion when trying to bring identical poles together. Field visualization using iron filings also demonstrates field-line crowding and opposition between like poles.
Why Other Options Are Wrong:
“Correct” contradicts fundamental behavior. Suggestions that weak fields, distance alone, or soft iron composition flip the rule are not applicable for two permanent magnets with poles aligned like-to-like.
Common Pitfalls:
Mistaking magnet–ferromagnet interactions (magnet attracts soft iron regardless of pole) for magnet–magnet interactions (which obey like-repel, unlike-attract).
Final Answer:
Incorrect
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