Logic Gates Question & AnswersJune 5, 2021 By WatElectronics This article lists 100+ Logic Gates MCQs for engineering students. All the Logic Gates Questions & Answers given below includes solution and link wherever possible to the relevant topic.A logic gate is a device and it performs logical operations on one or more than one logical inputs and produces a single output. The inputs for logic gates will be a digital signal and these logic gates perform mathematical operations. The XNOR, XOR, NOT, NAND, AND, OR, and NOR gates are the basic logic gates. The logic gates can be made from discrete components such as transistors, resistors, and diodes. 1). The logical gates are categorized into _______One groupTwo groupsThree groupsFour groupsHintThe logical gates are categorized into three groups they are basic gates, universal gates, and arithmetic gates 2). _______ are basic gatesNOTNANDANDNOT, AND, & ORHintNOT, AND, & OR are basic gates 3). __________ are universal gatesNOTNAND & NORANDNOT, AND, & ORHintNAND & NOR are universal gates 4). __________ are arithmetic gatesNOTNAND & NORX-OR & X-NORNOT, AND, & ORHintX-OR & X-NOR are arthematic gates 5). _________ are the common forms of complex logic gatesOR-AND-Invert (OAI)AND-OR-Invert (AOI)Both OAI and AOINone of the aboveHintBoth OAI and AOI are the common forms of complex logic gates 6). What is the standard form of DCDVS logic?Differential Cascade Voltage SwitchDifferential Cascade Voltage StaticDifferential Complex Voltage SwitchNone of the aboveHint The standard form of DCDVS logic is Differential Cascade Voltage Switch 7). What are the advantages of static complementary gates?ReliableNot easy to useNot reliableReliable and easy to useHintThe static complementary gates are reliable and easy to use 8). Who invented Boolean algebra?BardeenClaude ShannonGeorge BooleNone of the aboveHintGeorge Boole invented Boolean algebra 9). How many terminals do MOS transistors have?One b) c) d)TwoThreeFourHintMOS transistors have three terminals they are drain, gate, and source 10). _________ are the alternative form of canonical formSum of productsProduct of sumsBoth a and bNone of the aboveHintSum of products and product of sums is the alternative form of canonical form 11). The sum of products canonical forms also known as ________Minterm expansionDisjunctive normal formBoth a and bNone of the aboveHintThe sum of products canonical forms also known as minterm expansion and disjunctive normal form 12). The product of sums canonical forms also known as ________Maxterm expansionConjunctive normal formBoth a and bNone of the aboveHintThe product of sums canonical forms also known as maxterm expansion and conjunctive normal form 13). ______ is an example of identity lawa+0=0+a=a1+a=a+1=1ab=baa+(b+c)=(a+b)+cHint a+0=0+a=a is an example of identity law 14). ______ is an example of dominance lawa+0=0+a=a1+a=a+1=1ab=baa+(b+c)=(a+b)+cHint1+a=a+1=1 is an example of dominance law 15). ______ is an example of commutativity lawa+0=0+a=a1+a=a+1=1ab=baa+(b+c)=(a+b)+cHintab=ba is an example of commutativity law 16). ______ is an example of associativity lawa+0=0+a=a1+a=a+1=1ab=baa+(b+c)=(a+b)+cHinta+(b+c)=(a+b)+c is an example of associativity law 17). ______ is an example of distributive lawa+0=0+a=a1+a=a+1=1a+bc=(a+b)(a+c)a+(b+c)=(a+b)+cHinta+bc=(a+b)(a+c) is an example of distributive law 18). Combinational logic is used to ___________Compute outputsCompute new statesBoth a and bNone of the aboveHintCombinational logic is used to compute outputs and new states 19). The sequential logic contains ___________Memory elementsMemory is provided by feedbackBoth a and bNone of the aboveHintThe sequential logic contains memory elements and the memory is provided by feedback 20). _________ are the methods used to represent negative integer numbers1’s complimentSign magnitude2’s complimentAll of the aboveHintSign magnitude, 1’s compliment, and 2’s compliment are the methods used to represent negative integer numbers 21). How many types of number systems are there?OneTwoThreeFourHintThere are four types of number systems are there they are binary, decimal, hexadecimal, and octal 22). The base is 16 for _______ number systemBinaryHexadecimalDecimalOctalHintThe base is 16 for the hexadecimal number system 23). The American standard code for information interchange has _____ characters6425128None of the aboveHint The American standard code for information interchange has 128 characters 24). What is the standard form of ECDIC?Extended Binary Coded Decimal Interchange CodeExtended Binary Coded hexadecimal Interchange CodeExtended Binary Coded Decimal Information CodeNone of the aboveHintThe standard form of ECDIC is Extended Binary Coded Decimal Interchange Code 25). How many types of parities are there?OneTwoThreeFourHintThere are two types of parities are there they are odd parity and even parityLogic Gate MCQs for Quiz 26). The ones complement of binary number 1010 is ___________0101101001101110HintThe one's complement of binary number 1010 is 0101 27). The 2’s complement of binary number 1010 is ___________0101101001101110HintThe 2’s complement of binary number 1010 is 0110 28). The base is eight for _______ number systemBinaryHexadecimalDecimalOctalHintThe base is eight for the octal number system 29). How many types of IC packages are there?OneTwoThreeFourHintThere are two types of IC packages are there they are flat and dual-inline packages 30). IC’s are categorized into ____________OneTwoThreeFourHintIC’s are categorized into two types they are linear and digital 31). How many gates does ultra large scale integration contain?100 gates1000 gates10000 gatesMore than 100,000 gatesHintThe ULSI contains more than 100,000 gates per chip 32). How many gates does very large-scale integration contain?100 gates10,000 to 100,000 gates10000 gatesNone of the aboveHintThe VLSI contains 10,000 to 100,000 gates per chip 33). How many gates does large-scale integration contain?100 to 10,000 gates10,000 to 100,000 gates10000 gatesNone of the aboveHint The LSI contains 100 to 10,000 gates per chip 34). How many gates does medium-scale integration contain?100 to 10,000 gates10,000 to 100,000 gates10 to 100 gatesNone of the aboveHintThe medium-scale integration contains 10 to 100 gates per chip 35). How many gates does small-scale integration contain?100 to 10,000 gates10,000 to 100,000 gates10 to 100 gatesup to 10 gatesHintThe small-scale integration contains up to 10 gates per chip 36). The base is ten for _______ number systemBinaryHexadecimalDecimalOctalHintThe base is ten for the decimal number system 37). The base is two for _______ number systemBinaryHexadecimalDecimalOctalHintThe base is two for the binary number system 38). What are the advantages of ICs?Small in sizeLow-costOperating speed is highAll of the aboveHintICs are small in size, low cost and they have a high operating speed 39). Which IC is a quad two-input NAND gate?74LS0074LS0174LS03All of the aboveHint74LS00, 74LS01, and 74LS03 are the quad two-input NAND gate IC’s 40). The supply voltage of the 7400 series TTL family IC’s is __________1V2V4V5VHintThe supply voltage of the 7400 series TTL family IC’s is 5V 41). What is the standard form of TTL?Transistor-Transistor LogicTransistor Transducer LogicTransducer Transistor LogicNone of the aboveHintThe standard form of TTL is Transistor-Transistor Logic 42). The voltage range of low power Schottky is ________1V2V4V5VHintThe voltage range of low power Schottky is 5V 43).The maximum toggle speed of the 7400 TTL family ICs is _____20MHz10 MHz15 MHz25 MHzHintThe maximum toggle speed of the 7400 TTL family ICs is 25 MHz 44). The speed of the low power Schottky is _____2ns8ns10ns12nsHintThe speed of the low power Schottky is 10ns 45). The power of the low power Schottky is _____1mW2mW4mWNone of the aboveHintThe power of the low power Schottky is 2 mW 46). The voltage range of advanced low power Schottky is _____1V2V4V5VHintThe voltage range of advanced low power Schottky is 5V 47). The speed of the advanced low power Schottky is _____2ns7ns10ns12nsHintThe speed of the advanced low power Schottky is 7ns 48). The power of the advanced low power Schottky is _____1mW2mW4mWNone of the aboveHintThe power of the advanced low power Schottky is 1mW 49). The maximum input current of the silicon gate CMOS is ______0.1mA0.5mA±0.0001mANone of the aboveHintThe maximum input current of the silicon gate CMOS is ±0.0001mA 50). The maximum clock of silicon gate CMOS is ______20MHz40 MHz15 MHz25 MHzHintThe maximum clock of silicon gate CMOS is 40 MHzLogic Gate MCQs for Interviews 51). The propagation time delay of the silicon gate CMOS is _____2ns7ns10ns8nsHintThe propagation time delay of the silicon gate CMOS is 8ns 52). Which IC is quad two-input AND gate?74LS0874LS0074LS01All of the aboveHint74LS08 IC is quad two-input AND gate 53). The maximum input current of the metal gate CMOS is _________0.0001mA-0.0001mA c±0.0001mANone of the aboveHintThe maximum input current of the metal gate CMOS is -0.0001mA 54). The maximum clock of the metal gate CMOS is _________20MHz40 MHz12 MHz25 MHzHintThe maximum clock of the metal gate CMOS is 12 MHz 55). The propagation delay of the metal gate CMOS is ________2ns7ns10ns105nsHintThe propagation delay of the metal gate CMOS is 105ns 56). How many types of logic families are there?TwoFourSixSevenHint There are seven types of logic families are there they are RTL, DTL, IIL, TTL, ECL, MOS, and CMOS 57).What is the standard form of IIL?Injection Integrated LogicIntegrated Injection LogicIntegrated Integrated LogicNone of the aboveHintThe standard form of IIL is Integrated Injection Logic 58). The noise immunity is excellent in _____ logic familyCMOSTTLECLNone of the aboveHintThe noise immunity is excellent in CMOS logic family compare to TTL and ECL logic families 59). The maximum input current of the Schottky TTL gates is _________-2.0mA2.0mA-2.5mA-1.0mAHintThe maximum input current of the Schottky TTL gates is -2.0mA 60). The maximum clock of low power Schottky TTL is __________20MHz40 MHz12 MHz25 MHzHintThe maximum clock of low power Schottky TTL is 40 MHz 61). The propagation delay of the low power Schottky TTL is __________2ns7ns10ns105nsHintThe propagation delay of the low power Schottky TTL is 10ns 62). The fanout of the CMOS logic family is ______>10>20>30>50HintThe fanout of the CMOS logic family is >50 63). What are the components used in the RTL logic family?ResistorsTransistorsBoth a and bNone of the aboveHintBoth resistors and transistors are the components used in the RTL logic family 64). The TTL family is classified into __________TwoFourSixSevenHint The TTL family is classified into four domains they are standard TTL, TTL totem-pole, TTL open collector output, and TTL tristate logic 65). Which IC is a quad two-input NOR gate?74LS0274LS0174LS00None of the aboveHint74LS02 IC is a quad two-input NOR gate 66). The maximum input current of the low power Schottky TTL is ____________0.2mA0.3mA-0.4mA0.1mAHintThe maximum input current of the low power Schottky TTL is -0.4mA 67). The maximum clock of Schottky TTL gate is __________20MHz40 MHz12 MHz125 MHzHintThe maximum clock of Schottky TTL gate is 125 MHz 68). The propagation delay of Schottky TTL gate is ________3ns7ns10ns105nsHintThe propagation delay of the Schottky TTL gate is 3ns 69). The noise immunity is very good in _____ logic familyCMOSTTLECLNone of the aboveHintThe noise immunity is very good in the TTL logic family whereas the noise immunity is excellent in the CMOS logic family compared to other logic families 70). The fan-out of TTL logic family is __________25810HintThe fan out of the TTL logic family is 10 71). What are the components used in the DCTL logic family?ResistorstransistorsDiodesBoth a and bHintThe components used in the DCTL logic family is resistors and transistors 72). Which IC is a triple three-input AND gate?74LS1174LS1074LS12None of the aboveHint74LS11 IC is a triple three-input AND gate 73). The maximum input current of the advanced low power Schottky TTL gate is ________0.2mA0.3mA-0.4mA-0.1mAHintThe maximum input current of the advanced low power Schottky TTL gate is -0.1mA 74). The maximum clock of advanced low power Schottky TTL is __________70MHz40 MHz12 MHz25 MHzHintThe maximum clock of advanced low power Schottky TTL is 70MHz 75). The propagation delay of advanced low power Schottky TTL gate is ________3ns4ns10ns105nsHintThe propagation delay of the advanced low power Schottky TTL gate is 4ns 76). What are the components used in the TTL logic family?Resistors, TransistorsDiodesBoth a and bNone of the aboveHintThe components used in the TTL logic family are resistors, transistors, diodesLogic Gate MCQs for Exams 77). The RTL logic family has ______Poor noise marginPoor fan-outHigher speed and power dissipationAll of the aboveHintThe RTL logic family has a poor noise margin, poor fan out, higher speed, and power dissipation 78).Which IC is a triple three-input NAND gate?74LS1174LS1074LS27None of the aboveHint74LS10 IC is a triple three-input NAND gate 79). The maximum input current of the advanced Schottky TTL gate is _______0.2mA0.3mA-0.5mA-0.1mAHintThe maximum input current of the advanced Schottky TTL gate is -0.5mA 80). The maximum clock of advanced low power Schottky TTL is __________200MHz40 MHz12 MHz25 MHzHint The maximum clock of advanced low power Schottky TTL is 200MHz 81). The propagation delay of advanced Schottky TTL gate is ________3ns1.5ns10ns105nsHintThe propagation delay of the advanced Schottky TTL gate is 1.5ns 82). The noise immunity is good in _____ logic familyCMOSTTLECLNone of the aboveHintThe noise immunity is good in the ECL logic family, wherein CMOS noise immunity is excellent and in TTL it is very good 83). The fan-out of the ECL logic family is ________102025None of the aboveHintThe fan-out of the ECL logic family is 25 84). What are the components used in the DTL logic family?ResistorsDiodesTransistorsAll of the aboveHintThe components used in the DTL logic family are resistors, diodes, and transistors 85). Which IC is a triple three-input NOR gate?74LS1074LS1174LS27All of the aboveHint74LS27 IC is a triple three-input NOR gate 86). What are the components used in the ECL logic family?ResistorsTransistorsBoth a and bNone of the aboveHintThe components used in the ECL logic family are resistors and transistors 87). The DTL logic family has _________Improved noise margin and fan-outLow speedBoth a and bNone of the aboveHintThe DTL logic family has improved noise margin, improved fanout, but it has low speed 88). The power dissipation in RTL logic family is ______30mv40mv50mv60mvHintThe power dissipation in the RTL logic family is 30mv 89). In which logic family the power dissipation is very low?RTLDCTLCMOSTTLHintCMOS logic family always have low power dissipation 90). Which IC is a dual four-input NAND gate?74LS2074LS2174LS27None of the aboveHint74LS20 IC is a dual four-input NAND gate 91). What are the components used in COS logic family?PMOSNMOSBoth a and bNone of the aboveHintThe components used in the CMOS logic family are PMOS and NMOS 92). The power dissipation in the DTL logic family is ________1-12mv4-12mv6-12mv8-12mvHintThe power dissipation in the DTL logic family is 8-12mv 93). How many types of logic families are there?OneTwoThreeFourHintThere are two types of logic families are there they are bipolar and unipolar 94). Which one is a saturated bipolar logic family?RTLSchottky TTLECLNone of the aboveHintRTL belongs to the saturated bipolar logic family 95). Which one is an unsaturated bipolar logic family?RTLSchottky TTLDTLNone of the aboveHintSchottky TTL belongs to the unsaturated bipolar logic family 96). Which IC is a dual four-input AND gate?74LS1374LS2074LS21None of the aboveHint74LS21 IC is a dual four-input AND gate 97). The power dissipation in the ECL logic family is ______30mv40-55mv50-80mv60-90mvHintThe power dissipation in the ECL logic family is 40-55mv 98). Which one belongs to the unipolar logic family?RTL, DCTL, DTLTTL, ECLCMOS, PMOS, NMOSNone of the aboveHintCMOS, PMOS, and NMOS are belonged to the unipolar logic family 99). The basic gate of the TTL logic family is _____NANDNOTNORNone of the aboveHintThe basic gate of the TTL logic family is the NAND gate 100). The basic gate of the ECL logic family is _____NANDNOTOR/ NORNone of the aboveHintThe basic gate of the ECL logic family is OR/ NOR gatesLogic Gate Important MCQs with Hints 101). The basic gate of the CMOS logic family is _____NANDNOTNAND/ NORNone of the aboveHintThe basic gate of the CMOS logic family is NAND/ NOR 102). The noise immunity of TTL logic family is _________StrongGoodVery strongPoorHintThe noise immunity of the TTL logic family is strong compared to other logic families 103). Which IC is a hex NOT gate?74LS0474LS1974LS23None of the aboveHint74LS04 IC is a hex NOT gate 104). The power dissipation of TTL logic family is ____________30mv40mv10mv60mvHintThe power dissipation of the TTL logic family is 10mv 105). The noise margin in TTL logic family is _______ModerateLowHighNone of the aboveHintThe noise margin in the TTL logic family is moderate 106). What are the disadvantages of the ECL logic family?Noise immunity is worstPower consumption is highPower consumption is lowBoth a and bHintIn the ECL logic family the noise immunity is worst and the power consumption is high 107). For the ECL logic family the logic low voltage is about ______-1.5v to 1.60mv-1.75v to 1.80mv-1.7v to 1.75mvNone of the aboveHintFor the ECL logic family, the logic low voltage is about -1.7v to 1.75mv 108). For ECL logic family the logic high voltage is about ______-1.5v1.80mv1.75mv0.8vHintFor the ECL logic family, the logic high voltage is about 0.8v 109). The noise margin in the ECL logic family is _______ModerateLowHighNone of the aboveHintThe noise margin in the ECL logic family is low 110). The noise immunity of the ECL logic family is _________StrongGoodVery strongPoorHintThe noise immunity of the ECL logic family is good 111). IC 74LS belongs to _________logic familyLow power Schottky TTLFast power Schottky TTLAdvanced Schottky TTLAdvanced low power Schottky TTLHint IC 74LS belongs to low power Schottky TTL logic family 112). What are the merits of digital IC?Reduces the overall size of the systemReduces the overall cost of the systemReduces the overall cost power consumption of the systemAll of the aboveHintThe digital ICs reduces the overall size, cost, and power consumption of the system 113). What are the disadvantages of digital IC?Suitable for low power applicationsCan’t handle large powerBoth a and bNone of the aboveHintThe digital ICs are suitable for low power applications they can not handle large power Read more about Digital Circuits 114). What are the characteristics of the digital IC?Propagation delay, the figure of meritThreshold voltage, fan-in, fan-outPower dissipation, noise immunityOperating temperature, voltage, and current parametersAll of the aboveHintThe propagation delay, the figure of merit, threshold voltage, fan-in, fan-out, power dissipation, noise immunity, operating temperature, voltage, and current parameters are the characteristics of the digital IC 115). The noise immunity of the CMOS logic family is _________StrongGoodVery strongPoorHintThe noise immunity of the CMOS logic family is very strong 116). The noise margin in CMOS logic family is _______ModerateLowHighNone of the aboveHintThe noise margin in the CMOS logic family is high 117). __________ are the delay of the signal transition from input to outputPropagation delayThreshold voltagePower dissipationNone of the aboveHintPropagation delay is the delay of the signal transition from input to output 118). _______ explains how much power dissipated on the integrated chipPropagation delayThreshold voltagePower dissipationNone of the aboveHintPower dissipation explains how much power dissipated on the integrated chip 119). ________ is the multiplication of propagation delay and power dissipationPropagation delayThreshold voltagePower dissipationFigure of meritHintA figure of merit is the multiplication of propagation delay and power dissipation 120). ________ explains how many similar gates can be driven by a given logical gateFan-inFan-outPower dissipationFigure of meritHintFan-out explains how many similar gates can be driven by a given logical gateLogic Gate MCQs for Engineers 121). ________ explains how many inputs can be there with a given logical gateFan-inFan-outPower dissipationFigure of meritHintFan-in explains how many inputs can be there with a given logical gate 122). In IC’s the propagation delay is measured in terms of _______nsmvMHzNone of the aboveHintIn IC’s the propagation delay is measured in terms of nanoseconds 123). ________ are the advantages of insulated gate bipolar transistorIt has a high input impedanceIt has low ON state power lossIt has the best combination quality of BJT MOSFETAll of the aboveHintThe insulated gate bipolar transistor has high input impedance, low ON state power loss, and it has the best combination quality of BJT MOSFET 124). _______ is the Boolean expression of AND logic gateX=A+BX=A-BX=ABNone of the aboveHintX=A-B is the Boolean expression of AND logic gate 125). _______ is the Boolean expression of OR logic gateX=A+BX=A-BX=ABNone of the aboveHintX=A+B is the Boolean expression of OR logic gate Read more about Logic Gates 126). Which one is a AND gate IC?7408743274047400HintIC 7408 is a AND gate IC 127). The basic gate of the HTL logic family is _______NANDNORORNOTHintThe basic gate of the HTL logic family is the NAND gate 128). What are the features of the emitter coupled logic family?Fastest logic familyUsed in very high-frequency applicationsLarge fan-outAll of the aboveHintThe features of the emitter-coupled logic family are it is the fastest logic family, used in very high-frequency applications, and it has a very large fan-out 129). The fan-out of integrated injection logic is _________85Depends on injector currentNone of the aboveHintThe fan-out of integrated injection logic depends on the injector current 130). What are the limitations of the RTL?Low speedHigh power consumptionOperating speed is <4MHzAll of the aboveHintThe limitations of the RTL are it has low speed, high power consumption, and the operating speed is <4MHz 131). Which one is an OR gate IC?7408743274047400HintIC 7432 is an OR gate IC 132). The low power TTL is introduced in __________1989196419902000HintIn 1964 the low power TTL is introduced 133). What is the standard form of DCTL?Diode Coupled Transistor LogicDirect Coupled Transistor LogicDiode Coupled LogicNone of the aboveHintThe standard form of DCTL is Direct Coupled Transistor Logic 134). Which one is a NOT gate IC?7408743274047400HintIC 7404 is a NOT gate IC 135). What is the standard form of HTL?High Threshold LogicHigh Transistor LogicHigh Transition LogicNone of the aboveHintThe standard form of HTL is High Threshold Logic 136). __________ is the representation of decimal number 255 in binary format101010101011111111111111None of the aboveHint11111111 is the representation of decimal number 255 in binary format 137). How many bits does the 11001010 binary number system have?2 bits4 bits8 bits10 bitsHintThe binary number system 11001010 have 8 bits 138). Which one is a NAND gate IC?7408743274047400HintIC 7400 is a NAND gate IC 139). How many bits does the 101011 binary number system have?2 bits4 bits8 bits6 bitsHintThe binary number system 101011have 6 bits 140). How many inputs does AND have?Only oneOnly twoOnly threeOne or N inputsHintAND gate has one or N inputs 141). How many digits does the binary number system have?2486HintThe binary number system has two digits are one and zero 142). How many inputs does XOR gate have?Only oneOnly twoOnly threeOne or N inputsHintXOR gate has only two inputs 143). How many inputs does NOT gate have?Only oneOnly twoOnly threeOne or N inputsHintNOT gate has only one input 144). In the XNOR gate the output is low when the inputs are ______SameOppositeHintIn the XNOR gate, the output is low when the inputs are opposite 145). When both the inputs are low in the OR gate the output is _____HighLowHintWhen both the inputs are low in the OR gate the output is also low 146). Which one is an EX-OR gate IC?7408748674047400HintIC 7486 is an EX-OR gate IC 147). When one of the input is high in the OR gate then the output is _____HighLowHintWhen one of the input is high in the OR gate then the output is high 148). Which gate is also an inverter gate?NANDNOTANDORHintOR gate is also an inverter gate 149). _______ gate represents multiplication operationNANDNOTANDORHintAND gate represents multiplication operation 150). _______ gate represents the complement of the inputNANDNOTANDORHintNOT gate represents the complement of the input Time is Up! Time's up