Question Detail
Question
An inductor of inductance 4.0mH has a resistance of 15Ω. What is its impedance when its inductive reactance is equal to its resistance?
Correct Answer
Option A is the correct answer.
Detailed Explanation
When X_L = R = 15Ω, impedance Z = √(R² + X_L²) = √(15² + 15²) = 15√2 ≈ 21.2Ω.
Hint
If X_L equals R, impedance is simply R√2.