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Free download in PDF Op Amp Multiple Choice Questions with Answers for competitive exams. These objective type questions are very important for competitive exams like IIT-JEE, GATE, CAT etc. These short solved questions or quizzes are provided by Gkseries.
61
A certain inverting amplifier has a closed-loop voltage gain of 25. The Op-amp has an open-loop voltage gain of 100,000. If an Op-amp with an open-loop voltage gain of 200,000 is substituted in the arrangement, the closed-loop gain ……..
[A]
doubles
[B]
drops to 12.5
[C]
remains at 25
[D]
increases slightly
62
The Op-amp can amplify
[A]
a.c. signals only
[B]
d.c. signals only
[C]
both a.c. and d.c. signals
[D]
neither d.c. nor a.c. signals
Answer: both a.c. and d.c. signals
63
The tail current of a differential amplifier is …….
[A]
half of either collector current
[B]
equal to either collector current
[C]
two times either collector current
[D]
equal to the difference in base currents
Answer: two times either collector current
64
A common-mode signal is applied to ……….
[A]
the noninverting input
[B]
the inverting input
[C]
both iputs
[D]
top of the tail resistor
65
The common-mode gain is ………..
[A]
very high
[B]
very low
[C]
always unity
[D]
unpredictable
66
A certain OP-amp has bias currents of 50 µA. The input offset current is ……..
[A]
700 nA
[B]
99.3 µA
[C]
49.7 µA
[D]
none of these
67
For an Op-amp with negative feedback, the output is …….
[A]
equal to the input
[B]
increased
[C]
fed back to the inverting input
[D]
fed back to the noninverting input
Answer: fed back to the inverting input
68
The Op-amp can amplify
[A]
a.c. signals only
[B]
d.c. signals only
[C]
both a.c. and d.c. signals
[D]
neither d.c. nor a.c. signals
Answer: both a.c. and d.c. signals
69
The input offset current equals the ……….
[A]
difference between two base currents
[B]
average of two base currents
[C]
collector current divided by current gain
[D]
none of these
Answer: difference between two base currents
70
The tail current of a differential amplifier is …….
[A]
half of either collector current
[B]
equal to either collector current
[C]
two times either collector current
[D]
equal to the difference in base currents
Answer: two times either collector current
71
Current cannot flow to ground through …….
[A]
a mechanical ground
[B]
an a.c. ground
[C]
a virtual ground
[D]
an ordinary ground
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