Question

In an RC phase shift oscillator, the feedback network provides a phase shift of

• A. \(90^\circ\)
• B. \(180^\circ\)
• C. \(270^\circ\)
• D. \(360^\circ\)

Hint:

In RC phase shift oscillator, amplifier gives \(180^\circ\) and RC network gives \(180^\circ\), making total \(360^\circ\).

Answer 1

The Correct Option is B

Concept: For sustained oscillations, total phase shift around the feedback loop must be \(0^\circ\) or \(360^\circ\).

Step 1: In an RC phase shift oscillator, the amplifier provides: \[ 180^\circ \] phase shift.

Step 2: The RC feedback network must provide another: \[ 180^\circ \] phase shift.

Step 3: Total phase shift becomes: \[ 180^\circ+180^\circ=360^\circ \] Therefore, RC network provides: \[ \boxed{180^\circ} \]