The Operational Amplifier Mcqs | N4notes

The Operational Amplifier Mcqs

1. Negative feedback added to an op-amp _____ the bandwidth and _____ the gain.

  • A. increases, increases
  • B. increases, decreases
  • C. decreases, decreases
  • D. decreases, increases

2. A practical op-amp has very _____ input impedance, very _____ output impedance, very _____ open-loop voltage gain, and a _____ bandwidth.

  • A. high, low, high, wide
  • B. high, high, low, narrow
  • C. low, high, high, wide
  • D. low, low, low, wide

3. The input offset voltage drift is a parameter directly related to VOS and _____.

  • A. ID
  • B. power dissipation
  • C. temperature
  • D. phase shift

4. The maximum rate of change of the output voltage in response to a step input voltage is the _____ of an op-amp.

  • A. time constant
  • B. maximum frequency
  • C. slew rate
  • D. static discharge

5. A(n) _____ amplifier configuration has a higher input impedance and a lower output impedance than the op-amp itself.

  • A. non-inverting
  • B. inverting
  • C. voltage-follower
  • D. none of the above

6. A(n) _____ amplifier configuration has an input impedance approximately equal to the input resistor Ri and an output impedance approximately equal to the output impedance of the op-amp itself.

  • A. non-inverting
  • B. inverting
  • C. voltage-follower
  • D. none of the above

7. The _____ amplifier configuration has the highest input impedance and the lowest output impedance of the three basic op-amp configurations.

  • A. non-inverting
  • B. inverting
  • C. voltage-follower
  • D. none of the above

8. Open-loop voltage gain of an op-amp can range up to _____.

  • A. 10,000
  • B. 50,000
  • C. 100,000
  • D. 200,000

9. The ______ is the voltage gain of an op-amp with external feedback.

  • A. Aol
  • B. Acl
  • C. Av
  • D. none of the above

10. A three-stage op-amp can have a maximum phase lag of _____°.

  • A. –180
  • B. –90
  • C. –270
  • D. none of the above

11. A voltage-follower amplifier comes to you for service. You find the voltage gain to be 5.5 and the input impedance 22 kΩ. The probable fault in this amplifier, if any, is

  • A. the gain is too low for this type of amplifier.
  • B. the input impedance is too high for this amplifier.
  • C. nothing is wrong. The trouble must be somewhere else.
  • D. none of these.

12. An op-amp has an open-loop gain of 100,000 and a cutoff frequency of 40 Hz. Find the open-loop gain at a frequency of 30 Hz.

  • A. 800
  • B. 8,000
  • C. 80,000
  • D. 100,000

13. An op-amp has an open-loop gain of 75,000 and a cutoff frequency of 100 Hz. At 1 kHz the open-loop gain is down by

  • A. 10 dB.
  • B. 6 dB.
  • C. 20 dB.
  • D. 3 dB.

14. An RC network has R = 47 kΩ and C = 0.22 µF. What is the cutoff frequency?

  • A. 154 Hz
  • B. 1540 Hz
  • C. 1.54 Hz
  • D. 15.4 Hz

15. An RC network has R = 500 kΩ and C = 10 pF. Find the value of fc.

  • A. 31831 Hz
  • B. 31.831 kHz
  • C. 0.031831 MHz
  • D. all of the above

16. A certain op-amp has an open-loop voltage gain of 150,000. What is this gain expressed in dB?

  • A. 51.7 dB
  • B. 103.5 dB
  • C. 150,000 dB
  • D. 5.18 dB

17. The midrange open-loop gain of an op-amp is 135 dB. With negative feedback this gain is reduced to 72 dB. The closed-loop gain is

  • A. 135 dB.
  • B. 72 dB.
  • C. 207 dB.
  • D. 63 dB.

18. It takes an op-amp 22 µs to change its output from –15 V to +15 V. Determine the slew rate.

  • A. 1.36 V/µs
  • B. 0.68 V/µs
  • C. –0.68 V/µs
  • D. cannot determine