26. Which of the following improvements is (are) a result of the negative feedback in a circuit?
(a) Lower output impedance
(b) Reduced noise
(c) More linear operation
(d) All of the above
27. At what phase shift is the magnitude of βA at its maximum in the Nyquist plot?
(a) 90º
(b) 180º
(c) 270º
(d) 0º
28. Which of the following is (are) the determining factor(s) of the stability of a feedback amplifier?
(a) A
(b) Phase shift between input and output signals
(c) Both A and the phase shift between input and output signals
(d) None of the above
29. Only the condition βA = ________ must be satisfied for self-sustained oscillations to result.
(a) 0
(b) –1
(c) 1
(d) None of the above
30. An amplifier with negative feedback has ________ bandwidth than (as) the amplifier without feedback.
(a) the same
(b) less
(c) more
(d) None of the above
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