36. If voltage gain without feedback and feedback fraction are Av and mv respectively, then gain with negative voltage feedback is ……..
(a) Av/(1-Avmv)
(b) Av/(1+Avmv)
(c) (1+Avmv)/Av
(d) (1 + Av mv) Av
37. The output impedance of an emitter follower is ……..
(a) high
(b) very high
(c) almost zero
(d) low
38. The approximate voltage gain of an amplifier with negative voltage feedback (feedback fraction being mv) is ………
(a) 1/mv
(b) mv
(c) 1 /(1 + mv)
(d) 1 – mv
39. If Av and Afb are the voltage gains of an amplifier without feedback and with negative feedback respectively, then feedback fraction is …….
(a) (1/Av) – (1/Afb)
(b) (1/Av) + (1/Afb)
(c) (Av/Afb) + (1/Av)
(d) (1/Afb) – (1/Av)
40. In the expression for voltage gain with negative voltage feedback, the term 1 + Am mv is known as ……..
(a) gain factor
(b) feedback factor
(c) sacrifice factor
(d) none of the above
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