Calculate the gain of a negative-feedback amplifier having \(A=-2000\) and \(\beta=-1 / 10\).

Understanding the gain of an amplifier is crucial, as it determines how much an amplifier increases the strength of a signal. The gain is directly tied to the amplifier's efficacy. Calculating the gain of an amplifier, especially one with negative feedback, involves some specific steps.

The formula to determine the gain, represented as \(A'\), of a negative-feedback amplifier is \[A' = \frac{A}{1 + A \beta}\], where \(A\) is the open-loop gain, or the gain without feedback, and \(\beta\) is the feedback factor, a measure of how much of the output signal is returned to the input.

In the provided exercise, with \(A = -2000\) and \(\beta = -1 / 10\), the formula becomes \[A' = \frac{-2000}{1 + -2000(-1/10)}\], eventually providing the simplified gain as \(A' = -2000/201\). This is an essential concept as it demonstrates the significant effect that feedback has on the overall gain of the system.

Feedback is a pivotal concept in electronics, whereby a part of the output signal is 'fed back' into the input of a system. This can have various effects; it can stabilize the gain, improve linearity, broaden the bandwidth, or reduce the effects of noise and distortion.

Negative feedback, which is highlighted in our exercise, refers to the system where the feedback tends to reduce the output. The noteworthy point here is the sign of the feedback factor \(\beta\), which is negative. This negative value indicates that any increase in output is counteracted by a decrease at the input, serving to stabilize the system.

The importance of negative feedback extends from simple amplifiers to complex systems like control and communication systems, making it a foundational concept for students to grasp.

Operational amplifiers, or op-amps, are versatile components used in countless electronic circuits. They are designed to amplify voltage and are characterized by their high input impedance and low output impedance.

When analyzing an op-amp circuit, especially those with feedback, it's important to consider the open-loop gain, the feedback network, and how these affect the closed-loop gain. The open-loop gain is typically very high, suggesting it can amplify a tiny input signal to a significant degree. However, in practical applications, this is often controlled by introducing feedback.

The exercise involving the negative-feedback amplifier gives an insight into how feedback is used to manage the gain of an op-amp. It shows that through feedback mechanisms, the incredibly high gain of an op-amp can be tamed to a more practical level for a variety of applications, from audio equipment to signal processing circuits.