Question

With negative feedback, the returning signal:
A. Aids the input signal
B. Opposes the input signal
C. Is proportional to output current
D. Is proportional to differential voltage gain

Answer 1

We are talking about the feedback amplifiers and such amplifiers possess a feedback lane between the input and the output. There are two types of amplifiers which are positive feedback amplifier and negative feedback amplifier. As the name suggests in a negative feedback, there will be a decrease in the amplitude of the signal.

Complete answer:
The feedback-amplifier has been defined as an amplifier that has a feedback lane which exists between outputs to input. For such an amplifier, the feedback is the limitation that calculates the sum of feedback provided in the following amplifier. The feedback factor for an amplifier is defined as the ratio of the feedback signal and the input signal. The types of feedback amplifiers are as follows:

1. Positive Feedback amplifier: The positive feedback is defined as when the feedback current or voltage is applied for increasing input voltage, and then it is called positive feedback. Another name of this positive feedback is direct feedback. As positive feedback generates unnecessary distortion; it isn’t often used in amplifiers.

2. Negative Feedback Amplifier: The negative feedback is defined as if the feedback current or voltage can be applied for reducing the amplifier input, then it is called as negative feedback. Another name of this negative feedback is inverse feedback. This kind of feedback is regularly used in amplifier circuits.

Thus, option B is the correct answer.

Note: The phase opposition in negative feedback occurs as the amplifier provides 180o phase shift whereas the feedback network doesn’t. While the output energy is being applied to the input, for the voltage energy to be taken as feedback, the output is taken in shunt connection and for the current energy to be taken as feedback; the output is taken in series connection.