Difficulty: Easy
Correct Answer: False
Explanation:
Introduction / Context:
Electrical–magnetic analogies are widely used to reason about magnetic circuits with cores, air gaps, and windings. The common “Ohm’s law” form is mmf = flux * reluctance, which invites comparisons to V = I * R in electric circuits. This question checks whether the stated analogy is correct.
Given Data / Assumptions:
Concept / Approach:
The standard magnetic “Ohm’s law” is written as mmf = Φ * Rm. Compare with electric Ohm’s law V = I * R. Mapping terms shows mmf ↔ voltage, flux Φ ↔ current, and reluctance Rm ↔ resistance. Therefore, reluctance corresponds to resistance, not current.
Step-by-Step Solution:
Verification / Alternative check:
Check power-like quantities: electric power is V * I; magnetic “power” flow conceptually involves mmf * flux. The pairings remain consistent only if reluctance ↔ resistance and flux ↔ current.
Why Other Options Are Wrong:
“True” (and conditional variants) are incorrect because the analogy depends on the form of the governing equations, not on permeability being 1 or leakage being small.
Common Pitfalls:
Confusing flux density B with flux Φ; mixing field intensity H with mmf; assuming analogies change with material type. The core mapping remains mmf ↔ V, Φ ↔ I, Rm ↔ R.
Final Answer:
False.
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