Question

Operation of an Op-Amp with Negative feedback : A. Error voltage becomes very small
B. Output stabilizes
C. Input signal applied
D. Feedback signal is generated Choose the correct answer from the options given below :

• A. A, B, C, D
• B. B, A, D, C
• C. D, C, A, B
• D. C, D, A, B

Hint:

Negative feedback in Op-Amp: \[ \text{Input} \rightarrow \text{Feedback} \rightarrow \text{Small Error} \rightarrow \text{Stable Output} \] It improves stability and reduces distortion.

Answer 1

The Correct Option is D

Concept: An operational amplifier with negative feedback operates through a sequential process in which:
• an input signal is applied,
• a feedback signal is generated from output,
• the difference between input and feedback becomes very small,
• stable output operation is achieved. Negative feedback improves:
• stability,
• bandwidth,
• linearity,
• gain control.

Step 1: Applying the input signal. The first event is: \[ \text{Input signal applied} \] Without an input signal, the operational amplifier cannot begin operation. Hence: \[ C \] must occur first.

Step 2: Generation of feedback signal. Once output is produced, a portion of the output is fed back to the input. Thus: \[ \text{Feedback signal is generated} \] Therefore: \[ D \] comes next.

Step 3: Reduction of error voltage. The operational amplifier compares: \[ V_i \text{ and } V_f \] The difference: \[ V_e = V_i - V_f \] is called error voltage. Under negative feedback: \[ V_e \rightarrow \text{very small} \] Hence: \[ A \] comes after feedback generation.

Step 4: Output stabilization. Because negative feedback reduces error and controls gain:
• distortion reduces,
• gain becomes stable,
• output stabilizes. Hence: \[ B \] comes last.

Step 5: Writing the final sequence. Therefore correct sequence is: \[ C,\;D,\;A,\;B \] Hence correct option is: \[ \boxed{(4)} \]