# CSIR NET JRF: Electronics MCQs (Practice-Test 7 of 13)

1. An ideal OP-AMP is an ideal

1. Current controlled Current source

2. Current controlled Voltage source

3. Voltage controlled Voltage source

4. 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

1. 50KHz

2. 100KHz

3. 1000/17KHz

4. 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

1. 795mV

2. 395mV

3. 795mV

4. 39.5mV

4. The ideal OP-AMP has the following characteristics

1. Ri = ∞ A = ∞ R0 = 0

2. Ri = 0, A = ∞ R0 = 0

3. Ri = ∞ A = ∞ R0 = ∞

4. Ri = 0, A = ∞ R0 = ∞

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

1. 120k

2. 110k

3. 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

1. 10 V

2. 5 V

3. 5V

4. 5/2 V

7. Assume that the op-amp of the fig. Is ideal. If Vi is a triangular wave, then V0 will be

1. square wave

2. Triangular wave

3. Parabolic wave

4. 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

1. CMMR

2. bandwidth

3. slew rate

4. open-loop gain

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

1. 2

2. 1

3. ½

4. 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

1. 23dB

2. 25dB

3. 46dB

4. 50dB