Which of the following statements is FALSE for a negative feedback amplifier?

Concept of Negative Feedback Amplifier:

Negative feedback is a technique where a portion of the output signal is fed back to the input with opposite phase to improve amplifier performance. Key effects include:

• Stabilization of gain

• Reduction of distortion and noise

• Control of input/output impedances​

Additional Information

1) Reduces nonlinear distortion in the output

• True: Negative feedback linearizes the amplifier's response, reducing harmonic and intermodulation distortion.

2) Reduces the effect of temperature on the output

• True: By stabilizing the gain, negative feedback makes the amplifier less sensitive to temperature variations in components (e.g., transistor β shifts).

3) Reduces unwanted electrical signals (noise) generated in the circuit

• True: Feedback suppresses internally generated noise (e.g., thermal noise, hum) by the same factor as distortion.

4) Reduces the bandwidth of the amplifier

• False (Correct Answer):

  • Negative feedback increases bandwidth by trading gain for frequency response.

  • The gain-bandwidth product (GBW) remains constant: Lower midband gain → Higher cutoff frequency.