Difficulty: Easy
Correct Answer: inductive reactance increases with operating frequency
Explanation:
Introduction / Context:
Inductive reactance captures how an inductor resists changes in current when excited by alternating current. Understanding its dependence on frequency is crucial for filter design, impedance matching, and transient response prediction.
Given Data / Assumptions:
Concept / Approach:
The formula for inductive reactance is X_L = 2 * pi * f * L. This shows a direct proportionality: doubling frequency doubles X_L. At dc (f = 0), X_L = 0, meaning the inductor behaves like a short in steady state for pure dc.
Step-by-Step Solution:
Verification / Alternative check:
At dc, X_L = 0, confirming option B is false and reinforcing the proportional trend with frequency for nonzero f.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing capacitive reactance, which decreases with frequency, with inductive reactance, which increases.
Final Answer:
inductive reactance increases with operating frequency.
Discussion & Comments