For the given figure C(s)/R(s)

For the inner loop, transfer function =

Then .

For term the slope is -20 dB/decade or -6 dB/octave because - 20 log 2 = -6 dB.

Error is squared and integrated.

Voltage across capacitor lags by 90°.

The zero at - 1 gives the term (s + 1) in the numerator.

The poles at (- 2 + j1) and (- 2 - j1) give (s² + 4s + 5) term is the denominator. Gain is 2.

Join j₁ point with the zero and poles. Find magnitude and phase angles of all these lines.

If R_L is not infinite, the voltage ratio of potentiometer depends on the value of R_L. This is called loading effect.

Frequency is plotted on log scale and magnitude is taken in dB.

Arbitrary inputs require large bandwidth.

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