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Free download in PDF Op Amp Multiple Choice Questions & 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.
(21)
Calculate the cutoff frequency of a first-order low-pass filter for R1 = 2.5kΩ and C1 = 0.05μF
[A]
1.273kHz
[B]
12.73kHz
[C]
127.3 kHz
[D]
127.3 Hz
(22)
How many op-amps are required to implement this equation Vo = V1
(23)
An OPAMP has a slew rate of 5 V/μ S .The largest sine wave O/P voltage possible at a frequency of 1 MHZ is
[A]
10 volts
[B]
5 volts
[C]
5/ volts
[D]
5/2 volts
(24)
An ideal OP-AMP is an ideal
[A]
Current controlled Current source
[B]
Current controlled Voltage source
[C]
Voltage controlled Voltage source
[D]
Voltage controlled Current source
Answer: Voltage controlled Voltage source
(25)
A 741-Type OP-AMP has a gain-bandwith product of 1MHz. A non-inverting amplifier using this opamp & having a voltage gain of 20db will exhibit -3db bandwidth of
[A]
50KHz
[B]
100KHz
[C]
1000/17KHz
[D]
1000/7.07KHz
(26)
An opamp has a slew rate of 5V/ S. the largest sine wave o/p voltage possible at a frequency of 1MHz is
[A]
10 V
[B]
5 V
[C]
5V
[D]
5/2 V
(27)
Assume that the op-amp of the fig. is ideal. If Vi is a triangular wave, then V0 will be
[A]
Square wave
[B]
Triangular wave
[C]
Parabolic wave
[D]
Sine wave
(28)
A differential amplifier is invariably used in the i/p stage of all op-amps. This is done basically to provide the op-amps with a very high
[A]
CMMR
[B]
Bandwidth
[C]
Slew rate
[D]
Open-loop gain
(29)
In the differential voltage gain & the common mode voltage gain of a differential amplifier are 48db & 2db respectively, then its common mode rejection ratio is
[A]
23dB
[B]
25dB
[C]
46dB
[D]
50dB
(30)
Differential amplifiers are used in
[A]
Instrumentation amplifiers
[B]
Voltage followers
[C]
Voltage regulators
[D]
Buffers
Answer: Instrumentation amplifiers
31
For an ideal op-amp, which of the following is true?
[A]
The differential voltage across the input terminals is zero
[B]
The current into the input terminals is zero
[C]
The current from output terminal is zero
[D]
The output resistance is zero
Answer: The current from output terminal is zero
32
The two input terminals of an opamp are labeled as
[A]
High and low
[B]
Positive and negative
[C]
Inverting and non inverting
[D]
Differential ans non differential
Answer: Inverting and non inverting
33
For an op-amp having differential gain Av and common-mode gain Ac the CMRR is given by
[A]
Av + Ac
[B]
Av / Ac
[C]
1 + Av / Ac)
[D]
Ac / Av
34
Hysteresis is desirable in Schmitt-trigger, because
[A]
Energy is to be stored/discharged in parasitic capacitances
[B]
Effects of temperature would be compensated
[C]
Devices in the circuit should be allowed time for saturation and desaturation
[D]
It would prevent noise from causing false triggering
Answer: Devices in the circuit should be allowed time for saturation and desaturation
35
The output voltage Vo of the above circuit is
[A]
-6V
[B]
-5V
[C]
-1.2V
[D]
-0.2V
36
In differential-mode, …………….
[A]
opposite polarity signals are applied to the inputs
[B]
the gain is one
[C]
the outputs are of different amplitudes
[D]
only one supply voltage is used
Answer: opposite polarity signals are applied to the inputs
37
In the common mode, ……………
[A]
both inputs are grounded
[B]
the outputs are connected together
[C]
an identical signal appears on both the inputs
[D]
the output signal are in-phase
Answer: an identical signal appears on both the inputs
38
If ADM = 3500 and ACM = 0.35, the CMRR is ……….
[A]
1225
[B]
10,000
[C]
80 dB
[D]
(1) and (3)
39
A certain noninverting amplifier has Ri of 1 kO and Rf of 100 kO. The closed-loop voltage gain is ………
[A]
100,000
[B]
1000
[C]
101
[D]
100
40
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
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