Operational Amplifier Question & Answers June 5, 2021 By WatElectronics This article lists 100+ Operational Amplifier MCQs for engineering students. All the Operational Amplifier Questions & Answers given below include a hint and wherever possible link to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up their fundamentals on the Operational Amplifier topic. An operational amplifier also called OP-Amp and is a basic building block of analog-type electronic circuits. IC 741 is an op-amp invented by Karl D in 1967. It has 2 input terminals which are of differential voltage, where one of its input terminals is called inverting terminal represented as –V and another input terminal as +V, and a single output terminal Vout, which can be a source current and voltage or sink. The output obtained from an op-amp is an amplified value of the input signal. There are 4 types of gain in op-amps namely, voltage gain, current gain, transconductance gain, and trans resistance gain. Op-amp can perform operations such as logic and arithmetic. The advantage of an op-amp is it occupies less area, more reliable, low cost, low power consumption. The disadvantage of the Op-amp is designed for low-power operation only, not suitable for high output, and requires passive components. The applications of the op-amp are voltage comparator, Schmitt trigger, triangle wave oscillator, differentiator, and integrator. 1). Op-Amp is abbreviated as ________. Operational Amplifier Operand amplitude Operational amplitude None of the above None Hint Read more about Operational Amplifier. 2). Op-Amp is a ______ type of amplifier. Current Voltage Power Resistance None Hint 3). Op-Amp is ______ coupled voltage type of amplifier. AC DC ADC DAC None Hint 4). Op-Amp has _______ gain. High Low Zero Medium None Hint 5). A device with direct current coupled, high gain electronic voltage type amplifier with one output and differential input is called ______. Rectifier Amplifier Transformer Op-amp None Hint 6). Op-Amp has ________ inputs. Single Similar Zero Differential None Hint 7). Op-Amp has ________ outputs. Single Similar Multiple Differential None Hint 8). The potential output of Op-Amp is _____ times greater than the potential difference of input. 100 times 10000 times 100,000 times 10000000 times None Hint 9). Op-Amp is originated from ________ computers. Analog Digital Both a and b None of the above None Hint 10). Op-Amp performs ________ operations. Arithmetic Logical Alphanumeric Both a and b None Hint 11). Op-Amp performs which type of mathematical type operations. Linear Non-linear Frequency-dependent All the above None Hint 12). Op-Amp was invented by ________. Henry Richard Karl D David None Hint 13). Op-Amp was invented by Karl D in which year? 1966 1967 1968 1999 None Hint 14). Op-Amp has ______ input type configuration. 2 3 4 5 None Hint 15). Op-Amp with positive input type configuration is represented as _______. +V -V V Both a and c None Hint 16). Op-Amp with negative input type configuration is represented as _______. +V -V V Both a and c None Hint 17). Op-Amp with positive input type configuration +V or V is called _______. Non-inverting type input Inverting type input Non-inverting type output Inverting type output None Hint 18). Op-Amp with negative input type configuration -V is called _______. Non-inverting type input Inverting type input Non-inverting type output Inverting type output None Hint 19). Op-amp output is represented as _______. Vin Vout V+ V- None Hint 20). Op-Amp has how many terminals? 2 3 4 5 None Hint 21). +Vs is also called as ________. Positive power supply Negative power supply Both a and b Power supply None Hint 22). -Vs is also called ________. Positive power supply Negative power supply Both a and b Power supply None Hint 23). An op-amp with negative feedback provides _____ output parameter. Gain Bandwidth Input-output impedance All the above None Hint 24). Balancing type feedback is also called as _______. Positive type feedback Negative type feedback Both a and b None of the above None Hint 25). Which of the following are the examples of negative feedback? Mercury thermostats Centrifugal governors Steering engine All the above None Hint 26). Which of the following is a differential type of amplifier? Isolation amplifier Instrumentation amplifier Negative feedback amplifier All the above None Hint 27). A fully differential amplifier has _______ inputs. Similar Differential Zero None of the above None Hint 28). A fully differential amplifier has _______ outputs. Similar Differential Zero None of the above None Hint 29). FDA in FDA Op-amp stands for _______. Fully differential amplifier Finite differential amplifier Finite directional amplifier None of the above None Hint 30). An Instrumentational type amplifier is also called as _______. Instrumentation amplifier Insta amplifier Interior amplifier None of the above None Hint Read more about Instrumentation Amplifier. 31). Is an Instrumentational amplifier also called as In-Amp? Yes No Maybe None Hint 32). In-Amp is implemented with ______ type additional amplifier. Buffer amplifier Positive amplifier Negative amplifier None of the above None Hint 33). An Instrumentational type amplifier is built from how many op-amps? 1 2 3 4 None Hint 34). Buffer amplifier in In-Amp eliminates ______ type impedance matching. Output Input In-out None of the above None Hint 35). In-Amp is used for which of the following purpose? Test equipment Measure equipment Both a and b None of the above None Hint 36). Which of the following are the characteristics of In-Amp. Low DC offset Low drift High open-loop gain All the above None Hint 37). Voltage when applied at 2 inputs of Op-amp to get 0 V of output is called _____ voltage. Input offset Output offset In-out offset None of the above None Hint 38). An ideal Op-amp has _______ input voltage. 1V 3V Grounded Infinite None Hint 39). An ideal Op-amp has _______ output voltage. 1V 3V Grounded Infinite None Hint 40). Real-time Op-amps are ________ potentials. AC DC Zero Infinite None Hint Operational Amplifier MCQs for Interviews 41). CMRR parameter in an instrumentation amplifier stands for ________. Common mode rejection ratio Common medium rejection ratio Common mode ratio of reference None of the above None Hint 42). The ratio that quantifies the device's ability to reject the common mode signals is called ______. Common mode rejection ratio Gain ratio Common mode ratio of reference None of the above None Hint 43). Which of the following parameter of the instrumental op-amp circuit increases and allows the buffer to handle large data? Voltage gain Current gain CMRR All the above None Hint 44). What is the value of CMRR of an ideal instrumentation amplifier? 1 0 Infinity 0.5 None Hint 45). Instrumentation amplifier built with 2 op-amps has _______ gain. +2dB +3dB +6dB +8dB None Hint 46). Which of the following are the examples of instrumentation amplifiers? INA128 LT1167 MAX4194 All the above None Hint 47). Which of the following architecture can be designed as an instrumentation amplifier? Indirect current feedback Direct current feedback Indirect voltage feedback Direct voltage feedback None Hint 48). A feedback free instrumentation type amplifier has _____ input impedance. High Low 0 Medium None Hint 49). Which of the following amplifiers are built from 3 other op-amps? Differential amplifier Instrumentation amplifiers Isolation amplifiers Negative feedback amplifier None Hint 50). A amplifier that is similar to Instrumentation type amplifier but varies in common mode type voltage which destroys an ordinary op-amp is _____. Differential amplifier Instrumentation amplifiers Isolation amplifiers Negative feedback amplifier None Hint 51). Isolation type amplifier measures ______ type signals in presence of high CMM voltage. Large Small Zero Infinite None Hint Read more about Isolation Amplifier. 52). Isolation type amplifier provides ______ to the amplifier. Electrical safety barrier Electrical isolation Both a and b None of the above None Hint 53). Isolation type amplifier protects ______ components from CM potential voltage. Data acquisition Data transfer Current and voltage None of the above None Hint 54). Isolation type amplifier is commercially available as _______. Hybrid IC Merged IC Hierarchy IC None of the above None Hint 55). Which of the following methods of isolation type amplifier provide isolation property? Transformer isolated type amplifier Optically isolated type amplifier Amplifier with capacitors All the above None Hint 56). In a transformer isolated type amplifier, transformers coupling relies on ______ frequency of carrier signal. Low High Zero Infinite None Hint 57). The Bandwidth of transformer-isolated type amplifier ranges from _______. 2 to 20 kHz 2 to 20MHz 2 to 20 Hz None of the above None Hint 58). Which of the following are the components of the transformer isolate amplifier? Transformer Voltage to frequency type converter Frequency to voltage type converter All the above None Hint 59). Which of the following are the input components of the transformer isolate amplifier? Transformer Voltage to frequency type converter Frequency to voltage type converter None of the above None Hint 60). Which of the following are the output components of the transformer isolate amplifier? Transformer Voltage to frequency type converter Frequency to voltage type converter None of the above None Hint 61). Which of the following is the disadvantage of Op-amp ? Are designed for low power operation only Not suitable for high output Requires passive components All the above None Hint 62). An optically isolated type amplifier modulates the current via _____ optocoupler. LCD LED Driver Regulator None Hint 63). A device that transfers electrical type signals between 2 isolated circuits via light is called _____. Optocoupler Torch Battery None of the above None Hint 64). An optocoupler is available in ______ types. 6 5 7 8 None Hint 65). Resistive optocoupler is also called as ________. Vactrol Diode SCR None of the above None Hint 66). Which of the following are the sources of resistive optocoupler? Neon lamp Incandescent light bulb GaAs All the above None Hint 67). Which of the following is the light source used in the Resistive optocoupler? CdS Photo resistor LDR All the above None Hint 68). Resistive optocoupler has a transfer ratio of ________. <100% 50% 30% 20% None Hint 69). Which of the following is the light source used in the Resistive optocoupler? GaAs Infrared type LED LDR Both a and b None Hint 70). Which of the following is the light source used in the Diode optocoupler? GaAs Infrared type LED LDR Both a and b None Hint 71). Which of the following is the light source used in transistor optocoupler? GaAs Infrared type LED LDR Both a and b None Hint 72). Which of the following is the light source used in the SCR optocoupler? GaAs Infrared type LED LDR Both a and b None Hint 73). Which of the following is the light source used in triac optocoupler? GaAs Infrared type LED LDR Both a and b None Hint 74). Which of the following is the light source used in solid-state relay optocoupler? GaAs Infrared type LED GaAs stack Both b and c None Hint 75). Which of the following are the sensors used in vactrol type opto isolator? CdS LDR Silicon diode Both a and b None Hint 76). Which of the following is the sensor used in the diode type optoisolator? CdS LDR Silicon diode Both a and b None 77). Which of the following are the sensor used in transistor type opto isolator? Darlington photo transistor Bipolar silicon photo transistor Silicon diode Both a and b None Hint 78). Which of the following are the sensor used in type optoisolated triac? Darlington phototransistor Bipolar silicon phototransistor Silicon diode TRIAC None Hint 79). Which of the following are the sensor used in solid state relay? Darlington phototransistor Bipolar silicon phototransistor Stack of photodiodes that drives pair of IGBT and MOSFET TRIAC None Hint 80). MOSFET is abbreviated as _________. Metal oxide semiconductor field-effect transistor Metal oxygen semiconductor field effect transistor Metal oxide semiconductor field efficient transistor Metal oxide semiconductor field-effect transportation None Hint Read more about MOSFET. Operational Amplifier Exam Questions & Answers 81). IGBT is abbreviated as ________. Insulated gate bipolar transistor Isolation gate bipolar transistor Insulated gate bipolar transition Insulated gate bipolar thermistor None Hint Read more about IGBT. 82). IGBT contains _______ layers to control metal oxide semiconductor gate type structure. 2 3 4 7 None Hint 83). IGBT has a maximum voltage of ________. 3300V 2200V 1100V 4400V None Hint 84). IGBT has a current of __________. 1200 A 1100A 1000A 1500A None Hint 85). Which of the following are the applications of IGBT? RF amplifier Bipolar junction transistor Aerospace electronics All the above None Hint 86). IGBT combines which of the following characteristics of transistor? Power type MOSFET MESFET JFET All the above None Hint 87). IGBT in medium to high power applications are used in which of the following applications? Traction motor control Induction heating Switched-mode power supplies All the above None Hint 88). Which of the following are the advantages of IGBT? Low ON resistance High voltage capability Ease of drive All the above None Hint 89). Which of the following are the disadvantages of IGBT? High cost Latching problem Blocks high reverse voltage All the above None Hint 90). Which of the following are the advantages of MOSFET? High-efficiency High switching speed Low power consumption All the above None Hint 91). Which of the following are the disadvantages of MOSFET? Short life span Unstable Both a and b Less area None Hint 92). MOSFET are classified into _______ types. 2 3 4 5 None Hint Read more about Types of MOSFET. 93). Ideal Op-amp has _______ open loop gain. 0 Infinite Negative Positive None Hint 94). What is the equation of open loop gain of an ideal op-amp? Vout/Vin Vin/Vout Vin Vout None Hint 95). Ideal Op-amp has ________ input impedance. 0 Infinite Negative Positive None Hint 96). Ideal Op-amp has ________ input current. 0 Infinite Negative Positive None Hint 97). Ideal Op-amp has ________ input offset voltage. 0 Infinite Negative Positive None Hint 98). Ideal Op-amp has ________ output type voltage. 0 Infinite Negative Positive None Hint 99). Ideal Op-amp has ________ bandwidth. 0 Infinite Negative Positive None Hint 100). Ideal Op-amp has ________ noise. 0 Infinite Negative Positive None Hint 101). Ideal Op-amp has _________ output impedance. 0 Infinite Negative Positive None Hint 102). Ideal Op-amp has _________ CMMR. 0 Infinite Negative Positive None Hint 103). Ideal Op-amp has _______ power supply rejection ration. 0 Infinite Negative Positive None Hint 104). 741 Op-amp has _________ number of gain stages. 2 3 4 5 None Hint Read more about 741 Op-amp. 105). Which of the following are the 3 gain stages in Op-Amp? Differential amplifier Voltage amplifier Output amplifier All the above None Hint 106). A differential type amplifier in an Op-amp provides which of the following characteristics? Rejection of CM signal High input type impedance Low noise All the above None Hint 107). The difference between higher and lower frequencies in a continuous wave is called _______. Frequency Bandwidth Amplitude RMS value None Hint 108). Bandwidth is expressed in terms of ________. Bitrate Hertz Centimeters Seconds None Hint 109). The change in current or voltage or other electric value per unit of time is ________. Bandwidth Slew rate Frequency Offset value None Hint 110). Slew rate is expressed in terms of ________. Volts/ seconds Amperes/ seconds Seconds Both a and b None Hint 111). Power supply rejection ratio is also called as ________. Supply voltage rejection ratio Supply current rejection ratio Supply rejection ratio None of the above None Hint 112). An electronic circuit that suppresses power supply variation to the output signal is ______. Power supply rejection CMMR DC offset None of the above None Hint 113). PSRR is abbreviated as ________. Power supply rejection Power suspended rejection Power supply received Power supply receipting None Hint 114). _________ is defined as signal disturbance. Noise Music Sound All the above None Hint 115). Is the gain of the open loop amplifier is obtained from a feedback circuit? Yes No Maybe None Hint 116). An Op-amp has a maximum open loop gain of _________. 10dB 100dB 1000 dB 1 dB None Hint 117). Op-Amps open loop gain ________ when frequency increases. Increases Decreases Falls rapidly Become 0 None Hint 118). Does the real Op-amp have finite gain? Yes No Maybe None Hint 119). Open loop type DC gain of a real op-amp ranges from _________. 100000 to 1 million 100to 1 million 100 to 10,000 1 to 100 None Hint 120). The actual gain of the circuit in real op-amp is determined from ________. Positive feedback Negative feedback Both a and b Current flow None Hint Operational Amplifier Important Questions for Interviews 121). Does real Op-amp depend on open loop type gain? Yes No Maybe None Hint 122). If the closed loop gain of the real op-amp is high the feedback gain is _______. High low 0 <0 None Hint 123). The impedance considered from the 2 inputs of an op-am is called _______. Output impedance’ Input impedance Input resistance Output resistance None Hint 124). Impedance is symbolically represented as _________. R Z Y E None Hint 125). Resistance is symbolically represented as ________. R Z Y E None Hint 126). Admittance is symbolically represented as ________. R Z Y E None Hint 127). The impedance value taken between 1 input terminal of an op-amp to the ground is _______. Impedance Common mode input impedance Offset Output impedance None Hint 128). MOSFET input Op-amp circuit ______ if there is any input difference which is greater than the small threshold. Short circuits Open circuits Feedback Damages None Hint 129). MOSFET has ________ input impedance. High Low 0 Infinite None Hint 130). Which of the following are the important design parameters of typical op-amp applications? Leakage currents Input bias Output bias Both a and b None Hint 131). A real Op-amp has ________ output impedance. High Low 0 Infinity None Hint 132). A low impedance in the output of Op-amp circuit requires _______ quiescent value of current. Low High 0 Infinite None Hint 133). Which of the following are the applications of an op-amp? Voltage followers Selective inversion circuit Current to voltage converter All the above None Hint 134). Op-Amp 741 IC has _________ number of pins. 7 8 5 6 None Hint 135). Op-Amp 741 IC first pin specifies _________. Offset null -V +V -Vcc None Hint 136). Op-Amp 741 IC second pin specifies ________. Offset null -V +V -Vcc None Hint 137). OP-Amp 741 IC third pin specifies ________. Offset null -V +V -Vcc None Hint 138). OP-Amp 741 IC fourth pin specifies ________. Offset null -V +V -Vcc None Hint 139). OP-Amp 741 IC fifth pin specifies ________. Offset null Vout +Vcc NC None Hint 140). OP-Amp 741 IC sixth pin specifies ________. Offset null Vout +Vcc NC None Hint Operational Amplifier MCQs With Answers 141). OP-Amp 741 IC seventh pin specifies _______. Offset null Vout +Vcc NC None Hint 142). OP-Amp 741 IC eighth pin specifies _______. Offset null Vout +Vcc NC None Hint 143). Op-Amp has _______ number of gains. 2 3 4 5 None Hint 144). Voltage gain in op-amp is the ratio of __________. Vin/Vout Vout/Vin Iin/Iout Iout/ Iin None Hint 145). A current gain in op-amp is the ratio of _______. Vin/Vout Vout/Vin Iin/Iout Iout/ Iin None Hint 146). Transconductance gain in op-amp is the ratio of ________. Vin/Iout Vout/Vin Iin/Iout Iout/ Iin None Hint 147). Trans resistance gain in op-amp is the ratio of _________. Vin/Iout Vout/Vin Iin/Vout Iout/ Iin None Hint 148). Generally, an op-amp is a _________ stage amplifier. Single Double Multi Zero None Hint 149). Which of the following are the internal components of an op-amp? FET Transistors Resistors All the above None Hint 150). Op-Amp is available in the form of ________ package. IC Kit Device All the above None Hint 151). IC 741 can perform which of the following operations? Amplification Addition Integration All the above None Hint 152). An op-amp is denoted with arrow-headed represents _________. Flow of signal Input Output Ground None Hint 153). The signal applied at the input of inverting terminal of op-amp obtains _______ output signal. Amplified Cutoff Terminated None of the above None Hint 154). The signal, when applied at the input of inverting terminal of an op-amp, obtains an amplified output signal is of ______ degrees out of phase. 90 120 180 130 None Hint 155). The signal applied at the input of non-inverting terminal of op-amp obtains output signal as ______ phase. 90 Equal 0 130 None Hint 156). The voltage output of an ideal op-amp is _________. Vout= AOL(V1-V2) Vout= (V1-V2) Vout= AOL Vout= AOL(V1) None Hint 157). AOL of IC741 is ________. 2*100000 3 *100000 4*100000 5*100000 None Hint 158). Op-Amp differential input is represented as ________. V1+V2 V1 – V2 I1+I2 I-V None Hint 159). If the differential input of a differential op-amp is of certain value then, is the output obtained non zero? Yes No Maybe None Hint 160). Does a closed loop configuration have feedback? Yes No Maybe None Hint 161). Closed loop gain of the op-amp is equation is ________. VOUT=ACL*VD Vout= Acl Vout= Acl+Vd Vout= 0 None Hint 162). Op-Amp with positive feedback acts as ________. Oscillator Amplifier Rectifier Clipper None Hint 163). Op-Amp with negative feedback acts as ________. Oscillator Amplifier Rectifier Clipper None Hint 164). Which of the following are the requirements of an op-amp? Offset nulling Phase compensation Feedback All the above None Hint 165). When the output terminal of an op-amp is connected to its inverting input terminal then it is ______ feedback circuit. Positive Negative Both a and b None of the above None Hint 166). When the output terminal of an op-amp is connected to its non-inverting input terminal then it is _______ feedback circuit. Positive Negative Both a and b None of the above None Hint 167). Which of the following op-amp application doesn't have feedback? Voltage comparator Schmitt trigger Triangle wave oscillator Both b and c None Hint 168). Which of the following op-amp application have feedback? Voltage comparator Schmitt trigger Triangle wave oscillator Both b and c None Hint 169). IC 741 was invented by ________. Karl D Richard James Daniel None Hint 170). IC 741 was invented by Karl D in year _______. 1967 1988 1966 1981 None Hint 171). Which of the following are the advantages of an op-amp? Occupies less area More reliable Low cost, All the above None Hint 172). OP-Amp is a basic building block of _______ type electronic circuits. Analog Digital Both a and b None of the above None Hint Time's up
