Final answer:
The false statement regarding an operational amplifier with negative feedback is that the output signal is in-phase and amplified. Negative feedback actually results in the output being out of phase with the input.
Step-by-step explanation:
Regarding an operational amplifier (op-amp) with negative feedback, the statement that is not true is: B. output signal is in-phase and amplified. When negative feedback is applied to an op-amp, the output signal is usually out of phase with the input signal, which means that if the input goes positive, the output will go negative and vice versa. Negative feedback influences an op-amp in the following ways:
- A. the gain and bandwidth is reduced: Negative feedback stabilizes gain but can decrease the overall bandwidth.
- C. closed-loop gain is less than the open-loop gain: Using negative feedback, the gain of the op-amp is controlled by external resistors, resulting in a lower gain compared to the very high open-loop gain.
- D. the gain depends on the input and output impedance: While the gain does depend on external components, it is not directly dependent on input and output impedance but rather on the feedback network.
On the other hand, the amplitude of oscillations or signals can be affected by damping, feedback, and echoing, influencing whether the amplitude decreases, increases, or oscillates over time.