AExE01 · Chapter 1Basic Electrical & Electronics🏛️ Past Licensure QuestionID: 149d0b07
At the resonant frequency, what is the phase shift produced by the feedback network in a Wien Bridge oscillator?
At the resonant frequency, what is the phase shift produced by the feedback network in a Wien Bridge oscillator?
Multiple Choice Options
- A✓ Correct Option
0°
- B
45°
- C
90°
- D
180°
Detailed Technical Solution & Explanation
The lead-lag feedback network in a Wien Bridge oscillator consists of a series RC arm and a parallel RC arm. At the resonant frequency , the reactive effects of the series and parallel capacitors cancel out, resulting in a transfer function with exactly 0° phase shift.
Option Analysis:
•
Option A (0°): Correct. At resonance, the phase angle of the lead-lag feedback circuit is exactly 0°.
•
Option B (45°): Incorrect. Occurs at frequencies below resonance where leading phase predominates.
•
Option C (90°): Incorrect. High-frequency asymptotic behavior, not resonance.
•
Option D (180°): Incorrect. 180° phase shift is required in an RC phase shift oscillator, not a Wien bridge.
Reference: Mock Test 05NEC Licensure Syllabus