Operational amplifier MCQ Quiz (multiple choice questions) Leave a Comment / Electronics Multiple choice question MCQ online test Share this 0% 9 Created on July 03, 2023Basic electronics Operational Amplifier Operational amplifier (opamp) Multiple choice questions answers 1 / 36 Category: Operational amplifier 1. The input stage of an Op-amp is usually a ………. a. differential amplifier b. class B push-pull amplifier c. CE amplifier d. swamped amplifier 2 / 36 Category: Operational amplifier 2. For an Op-amp with negative feedback, the output is …… a. equal to the input b. increased c. fed back to the inverting input d. fed back to the noninverting input  Output voltage is proportional to input voltage only until it reaches the saturation voltage. The output cannot exceed the positive and negative saturation voltage. These saturation voltages are specified by an output voltage swing rating of the op-amp for given values of supply voltage. 3 / 36 Category: Operational amplifier 3. Which factor determine the output voltage of an op-amp? a. Positive saturation b. Negative saturation c. Both positive and negative saturation voltage d. Supply voltage 4 / 36 Category: Operational amplifier 4. The common-mode voltage gain of a differential amplifier is equal to RC divided by ……. a. r’e b. 2r’e c. r’e/2 d. 2RE 5 / 36 Category: Operational amplifier 5. A certain OP-amp has bias currents of 50 μA. The input offset current is …….. a. 700 nA b. 99.3 μA c. 49.7 μA d. none of these An ideal op-amp exhibits zero output resistance so that output can drive an infinite number of other devices. 6 / 36 Category: Operational amplifier 6. Which of the following electrical characteristics is not exhibited by an ideal op-amp? a. Infinite voltage gain b. Infinite bandwidth c. Infinite output resistance d. Infinite slew rate 7 / 36 Category: Operational amplifier 7. The use of negative feedback ……… a. reduces the voltage gain of an Op-amp b. makes the Op-amp oscillate c. makes linear operation possible d. answers (1) and (2) 8 / 36 Category: Operational amplifier 8. The common-mode voltage gain is ……… a. smaller than differentail voltage gain b. equal to differential voltage gain c. greater than differential voltage gain d. none of the above 9 / 36 Category: Operational amplifier 9. 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 10 / 36 Category: Operational amplifier 10. The op-amp can amplify a. a.c. signals only b. d.c. signals only c. both a.c. and d.c. signals d. neither d.c. nor a.c. signals 11 / 36 Category: Operational amplifier 11. 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 12 / 36 Category: Operational amplifier 12. A differential amplifier …………….. a. is a part of an Op-amp b. has one input and one output c. has two outputs d. answers (1) and (2) 13 / 36 Category: Operational amplifier 13.  Of the values listed, the most realistic value for open-loop voltage gain of an OP-amp is …… a. 1 b. 2000 c. 80 dB d. 100,000 14 / 36 Category: Operational amplifier 14. A common-mode signal is applied to ………. a. the noninverting input b. the inverting input c. both iputs d. top of the tail resistor 15 / 36 Category: Operational amplifier 15. With zero volts on both inputs, an OP-amp ideally should have an output ……….. a. equal to the positive supply voltage b. equal to the negative supply voltage c. equal to zero d. equal to CMRR 16 / 36 Category: Operational amplifier 16.  If the feedback resistor in Q15 (above question) is open, the voltage gain ……. a. increases b. decreases c. is not affected d. depends on Ri 17 / 36 Category: Operational amplifier 17. The node voltage at the top of the til resistor is closes to a. collector supply voltage b. zero c. emitter supply voltage d. tail current times base resistance The output voltage of an ideal op-amp is the product of gain and the algebraic difference between the two input voltages. 18 / 36 Category: Operational amplifier 18. Find the output voltage of an ideal op-amp. If V1 and V2 are the two input voltages a. VO= V1-V2 b. VO= A×(V1-V2) c. VO= A×(V1+V2) d. VO= V1×V2 19 / 36 Category: Operational amplifier 19. The common-mode gain is ……….. a. very high b. very low c. always unity d. unpredictable 20 / 36 Category: Operational amplifier 20. The tail current of a differential amplifier is ……. a. half of either collector current b. equal to either collector current c. two times either collector current d. equal to the difference in base currents 21 / 36 Category: Operational amplifier 21. A voltage follower ………. a. has a voltage gain of 1 b. is noninverting c. has no feedback resistor d. has all of these Explanation: The output voltage, VO = (Vin1– Vin2)=> 12v=3×(2- Vin2)=> Vin2= -2v. 22 / 36 Category: Operational amplifier 22. Find the input voltage of an ideal op-amp. It’s one of the inputs and output voltages are 2v and 12v. (Gain=3) a. 8v b. 4v c. -4v d. -2v 23 / 36 Category: Operational amplifier 23. The tail current in a differential amplifier equals ……. a. difference between two emitter currents b. sum of two emitter currents c. collector current divided by current gain d. collector voltage divided by collector resistance 24 / 36 Category: Operational amplifier 24. The output of a particular Op-amp increases 8V in 12μs. The slew rate is ……. a. 90 V/μs b. 0.67 V/μs c. 1.5 V/μs d. none of these Input resistance is infinite so almost any signal source can drive it and there is no loading of the preceding stage. 25 / 36 Category: Operational amplifier 25. Which is not the ideal characteristic of an op-amp? a. Input Resistance –> 0 b. Output impedance –> 0 c. Bandwidth –> ∞ d. Open loop voltage gain –> ∞ 26 / 36 Category: Operational amplifier 26. If ADM = 3500 and ACM = 0.35, the CMRR is ………. a. 1225 b. 10,000 c. 80 dB d. answers (1) and (3) 27 / 36 Category: Operational amplifier 27. The input impedance of a differential amplifier equals r’e a. β b. RE c. RC d. 2β 28 / 36 Category: Operational amplifier 28. 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 An ideal op-amp has infinite bandwidth. Therefore, any frequency signal from 0 to ∞ Hz can be amplified without attenuation. 29 / 36 Category: Operational amplifier 29. An ideal op-amp requires infinite bandwidth because a. Signals can be amplified without attenuation b. Output common-mode noise voltage is zero c. Output voltage occurs simultaneously with input voltage changes d. Output can drive infinite number of device 30 / 36 Category: Operational amplifier 30.  When a differential amplifier is operated single-ended, ………… a. the output is grounded b. one input is grounded and signal is applied to the other c. both inputs are connected together d. the output is not inverted 31 / 36 Category: Operational amplifier 31. The differential gain is ……… a. very high b. very low c. dependent on input voltage d. about 100 32 / 36 Category: Operational amplifier 32. Current cannot flow to ground through ……. a. a mechanical ground b. an a.c. ground c. a virtual ground d. an ordinary ground 33 / 36 Category: Operational amplifier 33. The input offset current equals the ………. a. difference between two base currents b. average of two base currents c. collector current divided by current gain d. none of these 34 / 36 Category: Operational amplifier 34. A certain noninverting amplifier has Ri of 1 kΩ and Rf of 100 kΩ. The closed-loop voltage gain is ……… a. 100,000 b. 1000 c. 101 d. 100 35 / 36 Category: Operational amplifier 35. The differential voltage gain of a differential amplifier is equal to RC divided by ……. a. r’e b. r’e/2 c. 2r’e d. RE 36 / 36 Category: Operational amplifier 36. Negative feedback ……….. a. increases the input and output impedances b. increases the input impedance and bandwidth c. decreases the output impedance and bandwidth d. does not affect impedance or bandwidth Your score is The average score is 4% LinkedIn Facebook Twitter VKontakte 0% Restart quiz Exit Anonymous feedback Thank you Send feedback Share this