Difficulty: Easy
Correct Answer: Mutual inductance
Explanation:
Introduction / Context:Transformers, wireless power transfer, and many sensing applications rely on one circuit inducing a response in another via magnetic fields. Knowing the correct terminology helps you read datasheets and design notes accurately.
Given Data / Assumptions:
Concept / Approach:The induced voltage in the second coil due to current change in the first is described by mutual inductance M. The coupling coefficient k (0 to 1) quantifies how much of the first coil’s flux links the second. Self-inductance L, by contrast, refers to voltage induced in the same coil that carries the changing current.
Step-by-Step Solution:
A changing current i1 in coil 1 creates a changing flux.A portion of that flux links coil 2, creating e2 = M * di1/dt.This cross-coupling is called mutual inductance.Therefore, the correct term is “Mutual inductance.”Verification / Alternative check:Transformers are practical demonstrations: primary current changes induce secondary voltages proportional to the mutual inductance (through the turns ratio framework).
Why Other Options Are Wrong:Electrical isolation: a benefit of transformer design but not the induction mechanism’s name.
Self-inductance: refers to a coil inducing voltage in itself from its own current change.
Coefficient of coupling: a dimensionless parameter k describing linkage efficiency, not the fundamental phenomenon’s name.
Common Pitfalls:Confusing mutual inductance with simple capacitive coupling. Assuming mutual inductance requires physical contact; it is through the magnetic field.
Final Answer:Mutual inductance
Discussion & Comments