CBSE (UGC)NET: Electronics MCQs (PracticeTest 7 of 13)

An ideal OPAMP is an ideal

Current controlled Current source

Current controlled Voltage source

Voltage controlled Voltage source

Voltage controlled Current source
Answer: b


A 741Type OPAMP has a gainbandwith product of 1MHz. A noninverting amplifier using this opamp & having a voltage gain of 20db will exhibit3db bandwidth of

50KHz

100KHz

1000/17KHz

1000/7.07KHz
Answer: a


An amplifier using an opamp with slew rate SR = 1v/sec has a gain of 40db. If this amplifier has to faithfully amplify sinusoidal signals from dc to 20KHz without introducing any slewrate induced distortion, then the input signal level exceed

795mV

395mV

795mV

39.5mV
Answer: c


The ideal OPAMP has the following characteristics

Ri = ∞ A = ∞ R0 = 0

Ri = 0, A = ∞ R0 = 0

Ri = ∞ A = ∞ R0 = ∞

Ri = 0, A = ∞ R0 = ∞
Answer: b


The approximate input impedance of the opamp circuit which has Ri = 10k, Rf = 100k, RL = 10k

∞

120k

110k

10k
Answer: c


An opamp has a slew rate of 5V/S. The largest sine wave o/p voltage possible at a frequency of 1MHz is

10 V

5 V

5V

5/2 V
Answer: a


Assume that the opamp of the fig. Is ideal. If Vi is a triangular wave, then V0 will be

square wave

Triangular wave

Parabolic wave

Sine wave


A differential amplifier is invariably used in the i/p stage of all opamps. This is done basically to provide the opamps with a very high

CMMR

bandwidth

slew rate

openloop gain
Answer: c


A differential amplifier has a differential gain of 20, 000. CMMR = 80dB. The common mode gain is given by

2

1

½

0
Answer: c


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

23dB

25dB

46dB

50dB
Answer: b
