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__Objective Questions from Opamp__

[1] 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

[2] 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

[3] 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 slew-rate induced distortion, then the input signal level exceed

A. 795mV

B. 395mV

C. 795mV

D. 39.5mV

[4] The ideal OP-AMP has the following characteristics

A. R

_{i}=∞,A=∞,R_{0}=0
B. R

_{i}=0,A=∞,R_{0}=0
C. R

_{i}=∞,A=∞,R_{0}=∞
D. R

_{i}=0,A=∞,R_{0}=∞[5] The approximate input impedance of the opamp circuit which has Ri=10k, Rf=100k, RL=10k

A. ∞

B. 120k

C. 110k

D. 10k

[6] 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

[7] 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

[8] 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

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

A. 2

B. 1

C. 1/2

D.0

[10] 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

answer of Q9 wroung. It must be A.2

ReplyDeleteyes it must be 2

Deleteyes it must be 2

Deleteit is 2

DeleteYep It is 2 Answer for 10 is also wrong ?

ReplyDeleteYes, it should be c) i.e. 46 db.

DeleteCMRR= Ad/Ac

20 log (CMRR)= 20 log Ad- 20 log Ac=48-2=46 db.

6 d

ReplyDelete