Question

Negative feedback in amplifiers A. improves the signal-to-noise ratio at the input. B. improves the signal-to-noise ratio at the output. C. does not affect the signal-to-noise ratio at the output. D. reduces distortion. Choose the correct answer from the options given below:

• A. A, C and D only
• B. B, C and D only
• C. A and C only
• D. B and D only

Hint:

Remember the four key benefits of negative feedback: it stabilizes gain, increases bandwidth, reduces distortion, and modifies input/output impedances. Its effect on SNR is complex, but it does not generally improve the SNR of the incoming signal.

Answer 1

The Correct Option is A

Negative feedback in amplifiers has the following effects:

• A: Improves the signal-to-noise ratio at the input. This is generally true because negative feedback helps in reducing noise, thereby improving the input signal-to-noise ratio.
• B: Improves the signal-to-noise ratio at the output. This statement is not true in all cases. Negative feedback can affect the output, but it doesn't necessarily improve the signal-to-noise ratio at the output.
• C: Does not affect the signal-to-noise ratio at the output. Negative feedback primarily helps in reducing distortion and can make the signal-to-noise ratio at the output less sensitive to changes in the amplifier gain, but it doesn't significantly alter it.
• D: Reduces distortion. Negative feedback is well known for reducing distortion by making the amplifier more linear.

Conclusion:

The correct answer is: A, C, and D only.