The reverse transmission factor, also known as the feedback ratio or the return ratio, is a parameter used in the analysis of feedback systems in electronics. It is denoted by the symbol β.

Explanation of the Answer:

The correct answer to the given question is option 'C', which states that the reverse transmission factor is the ratio of feedback by the output signal.

Let's break down the answer and explain it in detail:

1. Definition of the Reverse Transmission Factor:
The reverse transmission factor, β, is defined as the ratio of the feedback signal to the output signal in a feedback system. It represents the amount of output signal that is fed back to the input.

2. Feedback in a System:
In a feedback system, a portion of the output signal is fed back to the input to modify or control the system's behavior. This feedback signal is typically combined with the input signal to produce the system's output.

3. Importance of the Reverse Transmission Factor:
The reverse transmission factor is a crucial parameter in the analysis of feedback systems. It determines the amount of feedback signal that is applied to the input and affects the system's overall performance and stability.

4. Calculation of the Reverse Transmission Factor:
The reverse transmission factor, β, is calculated as the ratio of the feedback signal to the output signal. Mathematically, it can be expressed as:
β = Feedback Signal / Output Signal

5. Significance of the Reverse Transmission Factor:
The value of the reverse transmission factor determines the degree of feedback in a system. A higher value of β indicates a larger portion of the output signal being fed back to the input, leading to stronger feedback and potentially affecting the system's stability.

6. Role of the Reverse Transmission Factor in System Analysis:
The reverse transmission factor is used in various system analysis techniques, such as determining the closed-loop gain and stability of a feedback system. It helps in evaluating the impact of feedback on system performance and designing feedback control systems.

In conclusion, the reverse transmission factor is the ratio of feedback by the output signal in a feedback system. It plays a crucial role in analyzing and designing feedback systems, influencing their stability and performance.