FEEDBACK AMPLIFIERS AND OSCILLATORS Quiz

What is the condition for oscillations in a feedback amplifier?

• Phase shift of 180 degrees

• No phase shift

• Phase shift of 90 degrees

• Phase shift of 360 degrees or an integral multiple of 360 degrees

In a positive feedback amplifier, does the output signal have the same phase as the input signal or different phase?

• Different phase

• No phase

• Same phase

• Opposite phase

True or False: Positive feedback always leads to oscillations in an amplifier.

• Sometimes

• Depends on the weather

• False

• True

What is the phase shift between the input and output signals in a positive feedback amplifier?

• 270 degrees

• 180 degrees

• 90 degrees

• 0 degrees or 360 degrees

What happens to the gain of a positive feedback amplifier at the frequency of oscillation?

• Becomes negative

• Decreases

• Remains constant

• Infinite

What is the effect of positive feedback on the stability of an amplifier?

• It improves the sound quality of the amplifier.

• It has no effect on the stability of the amplifier.

• It reduces the stability of the amplifier.

• It increases the stability of the amplifier.

What is the role of phase shift in positive feedback oscillators?

• Phase shift stabilizes the oscillations

• Phase shift reduces the amplification

• Phase shift has no effect on oscillations

• Phase shift creates the conditions for sustained oscillations.

How does positive feedback affect the frequency of oscillation in an amplifier?

• Increases

• Has no effect

• Decreases

• Stabilizes