This question was previously asked in

TANGEDCO AE EE 2018 Official Paper

Option 2 : system gain

CT 1: Current Affairs (Government Policies and Schemes)

54560

10 Questions
10 Marks
10 Mins

Effect of negative feedback system:

- Negative feedback in a control system reduces the overall gain and increases stability.
- It reduces the sensitivity of output to input variation, distortion, and noise reduction.
- It improves bandwidth and input and output impedances (reducing impedance and increasing bandwidth which are desired in most cases)

__Note:__

In the open-loop system, we do not have any feedback path but in the closed-loop system, we have a feedback path.

The transfer function of the closed-loop transfer function, with the positive value of feedback gain is given by

\(\frac{{G\left( s \right)H\left( s \right)}}{{1 - G\left( s \right)H\left( s \right)}}\)

The overall gain of the transfer function increases with the positive value of feedback gain.

The transfer function of the closed-loop transfer function, with a negative value of feedback gain, is given

\(\frac{{G\left( s \right)H\left( s \right)}}{{1 + G\left( s \right)H\left( s \right)}}\)

The overall gain of the transfer function decreases with the negative value of feedback gain.