41. If the output impedance of an amplifier is Zout without feedback, then with negative voltage feedback, its value will be ………..
(a) Zout/(1+Avmv)
(b) Zout (1+Avmv)
(c) (1+Avmv)/Zout
(d) Zout (1-Avmv)
42. If the input impedance of an amplifier is Zin without feedback, then with negative voltage feedback, its value will be ………..
(a) Zin/(1+Avmv)
(b) Zin (1 + Av mv)
(c) (1+Avmv)/Zin
(d) Zin (1 – Av mv)
43. Feedback circuit ……… frequency.
(a) is independent of
(b) is strongly dependent on
(c) is moderately dependent on
(d) none of the above
44. The basic purpose of applying negative voltage feedback is to ………
(a) increase voltage gain
(b) reduce distortion
(c) keep the temperature within limits
(d) none of the above
45. If the voltage gain of an amplifier without feedback is 20 and with negative voltage feedback it is 12, then feedback fraction is ……..
(a) 5/3
(b) 3/5
(c) 1/5
(d) 0.033
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