- #1

roam

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## Homework Statement

I need some help with the following problem (it is from an old test paper).

Below is the Bode plot of the open loop gain of an amplifier:

A constant fraction β=0.1 of the output is fed back to the input. This feedback does not load the amplifier.

Using the Bode plot determine the frequency for which the magnitude of the loop gain of this circuit is equal to unity.

## The Attempt at a Solution

Clearly looking at the first graph ##|A|_{dB} = 1## at around ##1500 \ Hz##. I've marked this with a pen on the graph. But my answer was marked as incorrect. Why is that?

Clearly the graph touches 1 dB roughly at ##f = 1500 \ Hz##. So why is my answer wrong?

Any help is greatly appreciated.

P.S. The value of the amplifier's closed loop gain at DC was calculated to be -9.1.