Question

The total phase shift of loop in phase shift oscillator is

• A. \(45^\circ\)
• B. \(90^\circ\)
• C. \(180^\circ\)
• D. \(360^\circ\)

Hint:

Oscillation requires total loop phase shift = \(360^\circ\).

Answer 1

The Correct Option is D

Concept: For sustained oscillations (Barkhausen criterion): \[ \text{Total phase shift around loop} = 360^\circ \text{ (or } 0^\circ) \]

Step 1: Amplifier contribution In phase shift oscillator, amplifier provides \(180^\circ\) phase shift.

Step 2: RC network contribution Three RC sections provide additional \(180^\circ\).

Step 3: Total phase shift \[ 180^\circ + 180^\circ = 360^\circ \]

Step 4: Condition for oscillation Loop phase shift must be multiple of \(360^\circ\).

Step 5: Conclusion \[ \boxed{360^\circ} \]

Final Answer: \[ \boxed{(D)} \]