66. Nota
67. What is the ratio of the output impedance with series feedback to that without feedback?
(a) 1
(b) 1 + βA
(c) βA
(d) A
68. Determine the input impedance with feedback for a voltage-series feedback having A = –100, R1 = 15 kΩ, Ro = 20 kΩ, and a feedback of β = –0.25.
(a) 110 kΩ
(b) 290 kΩ
(c) 390 kΩ
(d) 510 kΩ
69. Determine the voltage gain with feedback for a voltage-series feedback having A = –100, R1 = 15 kΩ, R0 = 20 kΩ, and a feedback of β = –0.25.
(a) 3.85
(b) –3.85
(c) –9.09
(d) 9.09
70. An amplifier with a gain of –500 and a feedback of β = –0.1 has a gain change of 15% due to temperature. Calculate the change in gain of the feedback amplifier.
(a) 0.2%
(b) 0.3%
(c) 0.4%
(d) 0.5%
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