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 it performs logical operations on one or more than one logical input 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. The RTL, DTL, IIL, TTL, ECL, MOS, and CMOS are seven types of logic families.The logical gates are categorized into three groups they are basic gates, universal gates, and arithmetic gates. NOT, AND, & OR are basic gates, NAND & NOR are universal gates, X-OR & X-NOR are arthematic gates. The 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. Fan-in explains how many inputs can be there with a given logical gate whereas Fan-out explains how many similar gates can be driven by a given logical gate. 1). The logical gates are categorized into _______ One group Two groups Three groups Four groups HintThe logical gates are categorized into three groups they are basic gates, universal gates, and arithmetic gates2). _______ are basic gates NOT NAND AND NOT, AND, & OR HintNOT, AND, & OR are basic gates3). __________ are universal gates NOT NAND & NOR AND NOT, AND, & OR HintNAND & NOR are universal gates4). __________ are arithmetic gates NOT NAND & NOR X-OR & X-NOR NOT, AND, & OR HintX-OR & X-NOR are arthematic gates5). _________ are the common forms of complex logic gates OR-AND-Invert (OAI) AND-OR-Invert (AOI) Both OAI and AOI None of the above HintBoth OAI and AOI are the common forms of complex logic gates6). What is the standard form of DCDVS logic? Differential Cascade Voltage Switch Differential Cascade Voltage Static Differential Complex Voltage Switch None of the above Hint The standard form of DCDVS logic is Differential Cascade Voltage Switch7). What are the advantages of static complementary gates? Reliable Not easy to use Not reliable Reliable and easy to use HintThe static complementary gates are reliable and easy to use8). Who invented Boolean algebra? Bardeen Claude Shannon George Boole None of the above HintGeorge Boole invented Boolean algebra9). How many terminals do MOS transistors have? One b) c) d) Two Three Four HintMOS transistors have three terminals they are drain, gate, and source10). _________ are the alternative form of canonical form Sum of products Product of sums Both a and b None of the above HintSum of products and product of sums is the alternative form of canonical form11). The sum of products canonical forms also known as ________ Minterm expansion Disjunctive normal form Both a and b None of the above HintThe sum of products canonical forms also known as minterm expansion and disjunctive normal form12). The product of sums canonical forms also known as ________ Maxterm expansion Conjunctive normal form Both a and b None of the above HintThe product of sums canonical forms also known as maxterm expansion and conjunctive normal form13). ______ is an example of identity law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hint a+0=0+a=a is an example of identity law14). ______ is an example of dominance law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hint1+a=a+1=1 is an example of dominance law15). ______ is an example of commutativity law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hintab=ba is an example of commutativity law16). ______ is an example of associativity law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hinta+(b+c)=(a+b)+c is an example of associativity law17). ______ is an example of distributive law a+0=0+a=a 1+a=a+1=1 a+bc=(a+b)(a+c) a+(b+c)=(a+b)+c Hinta+bc=(a+b)(a+c) is an example of distributive law18). Combinational logic is used to ___________ Compute outputs Compute new states Both a and b None of the above HintCombinational logic is used to compute outputs and new states19). The sequential logic contains ___________ Memory elements Memory is provided by feedback Both a and b None of the above HintThe sequential logic contains memory elements and the memory is provided by feedback20). _________ are the methods used to represent negative integer numbers 1’s compliment Sign magnitude 2’s compliment All of the above HintSign magnitude, 1’s compliment, and 2’s compliment are the methods used to represent negative integer numbers21). How many types of number systems are there? One Two Three Four HintThere are four types of number systems are there they are binary, decimal, hexadecimal, and octal22). The base is 16 for _______ number system Binary Hexadecimal Decimal Octal HintThe base is 16 for the hexadecimal number system23). The American standard code for information interchange has _____ characters 64 25 128 None of the above Hint The American standard code for information interchange has 128 characters24). What is the standard form of ECDIC? Extended Binary Coded Decimal Interchange Code Extended Binary Coded hexadecimal Interchange Code Extended Binary Coded Decimal Information Code None of the above HintThe standard form of ECDIC is Extended Binary Coded Decimal Interchange Code25). How many types of parities are there? One Two Three Four HintThere are two types of parities are there they are odd parity and even parityLogic Gate MCQs for Quiz26). The ones complement of binary number 1010 is ___________ 0101 1010 0110 1110 HintThe one's complement of binary number 1010 is 010127). The 2’s complement of binary number 1010 is ___________ 0101 1010 0110 1110 HintThe 2’s complement of binary number 1010 is 011028). The base is eight for _______ number system Binary Hexadecimal Decimal Octal HintThe base is eight for the octal number system29). How many types of IC packages are there? One Two Three Four HintThere are two types of IC packages are there they are flat and dual-inline packages30). IC’s are categorized into ____________ One Two Three Four HintIC’s are categorized into two types they are linear and digital31). How many gates does ultra large scale integration contain? 100 gates 1000 gates 10000 gates More than 100,000 gates HintThe ULSI contains more than 100,000 gates per chip32). How many gates does very large-scale integration contain? 100 gates 10,000 to 100,000 gates 10000 gates None of the above HintThe VLSI contains 10,000 to 100,000 gates per chip33). How many gates does large-scale integration contain? 100 to 10,000 gates 10,000 to 100,000 gates 10000 gates None of the above Hint The LSI contains 100 to 10,000 gates per chip34). How many gates does medium-scale integration contain? 100 to 10,000 gates 10,000 to 100,000 gates 10 to 100 gates None of the above HintThe medium-scale integration contains 10 to 100 gates per chip35). How many gates does small-scale integration contain? 100 to 10,000 gates 10,000 to 100,000 gates 10 to 100 gates up to 10 gates HintThe small-scale integration contains up to 10 gates per chip36). The base is ten for _______ number system Binary Hexadecimal Decimal Octal HintThe base is ten for the decimal number system37). The base is two for _______ number system Binary Hexadecimal Decimal Octal HintThe base is two for the binary number system38). What are the advantages of ICs? Small in size Low-cost Operating speed is high All of the above HintICs are small in size, low cost and they have a high operating speed39). Which IC is a quad two-input NAND gate? 74LS00 74LS01 74LS03 All of the above Hint74LS00, 74LS01, and 74LS03 are the quad two-input NAND gate IC’s40). The supply voltage of the 7400 series TTL family IC’s is __________ 1V 2V 4V 5V HintThe supply voltage of the 7400 series TTL family IC’s is 5V41). What is the standard form of TTL? Transistor-Transistor Logic Transistor Transducer Logic Transducer Transistor Logic None of the above HintThe standard form of TTL is Transistor-Transistor Logic42). The voltage range of low power Schottky is ________ 1V 2V 4V 5V HintThe voltage range of low power Schottky is 5V43).The maximum toggle speed of the 7400 TTL family ICs is _____ 20MHz 10 MHz 15 MHz 25 MHz HintThe maximum toggle speed of the 7400 TTL family ICs is 25 MHz44). The speed of the low power Schottky is _____ 2ns 8ns 10ns 12ns HintThe speed of the low power Schottky is 10ns45). The power of the low power Schottky is _____ 1mW 2mW 4mW None of the above HintThe power of the low power Schottky is 2 mW46). The voltage range of advanced low power Schottky is _____ 1V 2V 4V 5V HintThe voltage range of advanced low power Schottky is 5V47). The speed of the advanced low power Schottky is _____ 2ns 7ns 10ns 12ns HintThe speed of the advanced low power Schottky is 7ns48). The power of the advanced low power Schottky is _____ 1mW 2mW 4mW None of the above HintThe power of the advanced low power Schottky is 1mW49). The maximum input current of the silicon gate CMOS is ______ 0.1mA 0.5mA ±0.0001mA None of the above HintThe maximum input current of the silicon gate CMOS is ±0.0001mA50). The maximum clock of silicon gate CMOS is ______ 20MHz 40 MHz 15 MHz 25 MHz HintThe maximum clock of silicon gate CMOS is 40 MHzLogic Gate MCQs for Interviews51). The propagation time delay of the silicon gate CMOS is _____ 2ns 7ns 10ns 8ns HintThe propagation time delay of the silicon gate CMOS is 8ns52). Which IC is quad two-input AND gate? 74LS08 74LS00 74LS01 All of the above Hint74LS08 IC is quad two-input AND gate53). The maximum input current of the metal gate CMOS is _________ 0.0001mA -0.0001mA c ±0.0001mA None of the above HintThe maximum input current of the metal gate CMOS is -0.0001mA54). The maximum clock of the metal gate CMOS is _________ 20MHz 40 MHz 12 MHz 25 MHz HintThe maximum clock of the metal gate CMOS is 12 MHz55). The propagation delay of the metal gate CMOS is ________ 2ns 7ns 10ns 105ns HintThe propagation delay of the metal gate CMOS is 105ns56). How many types of logic families are there? Two Four Six Seven Hint There are seven types of logic families are there they are RTL, DTL, IIL, TTL, ECL, MOS, and CMOS57).What is the standard form of IIL? Injection Integrated Logic Integrated Injection Logic Integrated Integrated Logic None of the above HintThe standard form of IIL is Integrated Injection Logic58). The noise immunity is excellent in _____ logic family CMOS TTL ECL None of the above HintThe noise immunity is excellent in CMOS logic family compare to TTL and ECL logic families59). The maximum input current of the Schottky TTL gates is _________ -2.0mA 2.0mA -2.5mA -1.0mA HintThe maximum input current of the Schottky TTL gates is -2.0mA60). The maximum clock of low power Schottky TTL is __________ 20MHz 40 MHz 12 MHz 25 MHz HintThe maximum clock of low power Schottky TTL is 40 MHz61). The propagation delay of the low power Schottky TTL is __________ 2ns 7ns 10ns 105ns HintThe propagation delay of the low power Schottky TTL is 10ns62). The fanout of the CMOS logic family is ______ >10 >20 >30 >50 HintThe fanout of the CMOS logic family is >5063). What are the components used in the RTL logic family? Resistors Transistors Both a and b None of the above HintBoth resistors and transistors are the components used in the RTL logic family64). The TTL family is classified into __________ Two Four Six Seven Hint The TTL family is classified into four domains they are standard TTL, TTL totem-pole, TTL open collector output, and TTL tristate logic65). Which IC is a quad two-input NOR gate? 74LS02 74LS01 74LS00 None of the above Hint74LS02 IC is a quad two-input NOR gate66). The maximum input current of the low power Schottky TTL is ____________ 0.2mA 0.3mA -0.4mA 0.1mA HintThe maximum input current of the low power Schottky TTL is -0.4mA67). The maximum clock of Schottky TTL gate is __________ 20MHz 40 MHz 12 MHz 125 MHz HintThe maximum clock of Schottky TTL gate is 125 MHz68). The propagation delay of Schottky TTL gate is ________ 3ns 7ns 10ns 105ns HintThe propagation delay of the Schottky TTL gate is 3ns69). The noise immunity is very good in _____ logic family CMOS TTL ECL None of the above HintThe 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 families70). The fan-out of TTL logic family is __________ 2 5 8 10 HintThe fan out of the TTL logic family is 1071). What are the components used in the DCTL logic family? Resistors transistors Diodes Both a and b HintThe components used in the DCTL logic family is resistors and transistors72). Which IC is a triple three-input AND gate? 74LS11 74LS10 74LS12 None of the above Hint74LS11 IC is a triple three-input AND gate73). The maximum input current of the advanced low power Schottky TTL gate is ________ 0.2mA 0.3mA -0.4mA -0.1mA HintThe maximum input current of the advanced low power Schottky TTL gate is -0.1mA74). The maximum clock of advanced low power Schottky TTL is __________ 70MHz 40 MHz 12 MHz 25 MHz HintThe maximum clock of advanced low power Schottky TTL is 70MHz75). The propagation delay of advanced low power Schottky TTL gate is ________ 3ns 4ns 10ns 105ns HintThe propagation delay of the advanced low power Schottky TTL gate is 4ns76). What are the components used in the TTL logic family? Resistors, Transistors Diodes Both a and b None of the above HintThe components used in the TTL logic family are resistors, transistors, diodesLogic Gate MCQs for Exams77). The RTL logic family has ______ Poor noise margin Poor fan-out Higher speed and power dissipation All of the above HintThe RTL logic family has a poor noise margin, poor fan out, higher speed, and power dissipation78).Which IC is a triple three-input NAND gate? 74LS11 74LS10 74LS27 None of the above Hint74LS10 IC is a triple three-input NAND gate79). The maximum input current of the advanced Schottky TTL gate is _______ 0.2mA 0.3mA -0.5mA -0.1mA HintThe maximum input current of the advanced Schottky TTL gate is -0.5mA80). The maximum clock of advanced low power Schottky TTL is __________ 200MHz 40 MHz 12 MHz 25 MHz Hint The maximum clock of advanced low power Schottky TTL is 200MHz81). The propagation delay of advanced Schottky TTL gate is ________ 3ns 1.5ns 10ns 105ns HintThe propagation delay of the advanced Schottky TTL gate is 1.5ns82). The noise immunity is good in _____ logic family CMOS TTL ECL None of the above HintThe noise immunity is good in the ECL logic family, wherein CMOS noise immunity is excellent and in TTL it is very good83). The fan-out of the ECL logic family is ________ 10 20 25 None of the above HintThe fan-out of the ECL logic family is 2584). What are the components used in the DTL logic family? Resistors Diodes Transistors All of the above HintThe components used in the DTL logic family are resistors, diodes, and transistors85). Which IC is a triple three-input NOR gate? 74LS10 74LS11 74LS27 All of the above Hint74LS27 IC is a triple three-input NOR gate86). What are the components used in the ECL logic family? Resistors Transistors Both a and b None of the above HintThe components used in the ECL logic family are resistors and transistors87). The DTL logic family has _________ Improved noise margin and fan-out Low speed Both a and b None of the above HintThe DTL logic family has improved noise margin, improved fanout, but it has low speed 88). The power dissipation in RTL logic family is ______ 30mv 40mv 50mv 60mv HintThe power dissipation in the RTL logic family is 30mv89). In which logic family the power dissipation is very low? RTL DCTL CMOS TTL HintCMOS logic family always have low power dissipation90). Which IC is a dual four-input NAND gate? 74LS20 74LS21 74LS27 None of the above Hint74LS20 IC is a dual four-input NAND gate91). What are the components used in COS logic family? PMOS NMOS Both a and b None of the above HintThe components used in the CMOS logic family are PMOS and NMOS92). The power dissipation in the DTL logic family is ________ 1-12mv 4-12mv 6-12mv 8-12mv HintThe power dissipation in the DTL logic family is 8-12mv93). How many types of logic families are there? One Two Three Four HintThere are two types of logic families are there they are bipolar and unipolar94). Which one is a saturated bipolar logic family? RTL Schottky TTL ECL None of the above HintRTL belongs to the saturated bipolar logic family95). Which one is an unsaturated bipolar logic family? RTL Schottky TTL DTL None of the above HintSchottky TTL belongs to the unsaturated bipolar logic family96). Which IC is a dual four-input AND gate? 74LS13 74LS20 74LS21 None of the above Hint74LS21 IC is a dual four-input AND gate97). The power dissipation in the ECL logic family is ______ 30mv 40-55mv 50-80mv 60-90mv HintThe power dissipation in the ECL logic family is 40-55mv98). Which one belongs to the unipolar logic family? RTL, DCTL, DTL TTL, ECL CMOS, PMOS, NMOS None of the above HintCMOS, PMOS, and NMOS are belonged to the unipolar logic family99). The basic gate of the TTL logic family is _____ NAND NOT NOR None of the above HintThe basic gate of the TTL logic family is the NAND gate100). The basic gate of the ECL logic family is _____ NAND NOT OR/ NOR None of the above HintThe basic gate of the ECL logic family is OR/ NOR gatesLogic Gate Important MCQs with Hints101). The basic gate of the CMOS logic family is _____ NAND NOT NAND/ NOR None of the above HintThe basic gate of the CMOS logic family is NAND/ NOR102). The noise immunity of TTL logic family is _________ Strong Good Very strong Poor HintThe noise immunity of the TTL logic family is strong compared to other logic families103). Which IC is a hex NOT gate? 74LS04 74LS19 74LS23 None of the above Hint74LS04 IC is a hex NOT gate104). The power dissipation of TTL logic family is ____________ 30mv 40mv 10mv 60mv HintThe power dissipation of the TTL logic family is 10mv105). The noise margin in TTL logic family is _______ Moderate Low High None of the above HintThe noise margin in the TTL logic family is moderate106). What are the disadvantages of the ECL logic family? Noise immunity is worst Power consumption is high Power consumption is low Both a and b HintIn the ECL logic family the noise immunity is worst and the power consumption is high107). For the ECL logic family the logic low voltage is about ______ -1.5v to 1.60mv -1.75v to 1.80mv -1.7v to 1.75mv None of the above HintFor the ECL logic family, the logic low voltage is about -1.7v to 1.75mv108). For ECL logic family the logic high voltage is about ______ -1.5v 1.80mv 1.75mv 0.8v HintFor the ECL logic family, the logic high voltage is about 0.8v109). The noise margin in the ECL logic family is _______ Moderate Low High None of the above HintThe noise margin in the ECL logic family is low110). The noise immunity of the ECL logic family is _________ Strong Good Very strong Poor HintThe noise immunity of the ECL logic family is good111). IC 74LS belongs to _________logic family Low power Schottky TTL Fast power Schottky TTL Advanced Schottky TTL Advanced low power Schottky TTL Hint IC 74LS belongs to low power Schottky TTL logic family112). What are the merits of digital IC? Reduces the overall size of the system Reduces the overall cost of the system Reduces the overall cost power consumption of the system All of the above HintThe digital ICs reduces the overall size, cost, and power consumption of the system113). What are the disadvantages of digital IC? Suitable for low power applications Can’t handle large power Both a and b None of the above HintThe digital ICs are suitable for low power applications they can not handle large power Read more about Digital Circuits114). What are the characteristics of the digital IC? Propagation delay, the figure of merit Threshold voltage, fan-in, fan-out Power dissipation, noise immunity Operating temperature, voltage, and current parameters All of the above HintThe 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 IC115). The noise immunity of the CMOS logic family is _________ Strong Good Very strong Poor HintThe noise immunity of the CMOS logic family is very strong116). The noise margin in CMOS logic family is _______ Moderate Low High None of the above HintThe noise margin in the CMOS logic family is high117). __________ are the delay of the signal transition from input to output Propagation delay Threshold voltage Power dissipation None of the above HintPropagation delay is the delay of the signal transition from input to output118). _______ explains how much power dissipated on the integrated chip Propagation delay Threshold voltage Power dissipation None of the above HintPower dissipation explains how much power dissipated on the integrated chip119). ________ is the multiplication of propagation delay and power dissipation Propagation delay Threshold voltage Power dissipation Figure of merit HintA figure of merit is the multiplication of propagation delay and power dissipation120). ________ explains how many similar gates can be driven by a given logical gate Fan-in Fan-out Power dissipation Figure of merit HintFan-out explains how many similar gates can be driven by a given logical gateLogic Gate MCQs for Engineers121). ________ explains how many inputs can be there with a given logical gate Fan-in Fan-out Power dissipation Figure of merit HintFan-in explains how many inputs can be there with a given logical gate122). In IC’s the propagation delay is measured in terms of _______ ns mv MHz None of the above HintIn IC’s the propagation delay is measured in terms of nanoseconds123). ________ are the advantages of insulated gate bipolar transistor It has a high input impedance It has low ON state power loss It has the best combination quality of BJT MOSFET All of the above HintThe insulated gate bipolar transistor has high input impedance, low ON state power loss, and it has the best combination quality of BJT MOSFET124). _______ is the Boolean expression of AND logic gate X=A+B X=A-B X=AB None of the above HintX=A-B is the Boolean expression of AND logic gate125). _______ is the Boolean expression of OR logic gate X=A+B X=A-B X=AB None of the above HintX=A+B is the Boolean expression of OR logic gate Read more about Logic Gates126). Which one is a AND gate IC? 7408 7432 7404 7400 HintIC 7408 is a AND gate IC127). The basic gate of the HTL logic family is _______ NAND NOR OR NOT HintThe basic gate of the HTL logic family is the NAND gate128). What are the features of the emitter coupled logic family? Fastest logic family Used in very high-frequency applications Large fan-out All of the above HintThe 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-out129). The fan-out of integrated injection logic is _________ 8 5 Depends on injector current None of the above HintThe fan-out of integrated injection logic depends on the injector current130). What are the limitations of the RTL? Low speed High power consumption Operating speed is <4MHz All of the above HintThe limitations of the RTL are it has low speed, high power consumption, and the operating speed is <4MHz131). Which one is an OR gate IC? 7408 7432 7404 7400 HintIC 7432 is an OR gate IC132). The low power TTL is introduced in __________ 1989 1964 1990 2000 HintIn 1964 the low power TTL is introduced133). What is the standard form of DCTL? Diode Coupled Transistor Logic Direct Coupled Transistor Logic Diode Coupled Logic None of the above HintThe standard form of DCTL is Direct Coupled Transistor Logic134). Which one is a NOT gate IC? 7408 7432 7404 7400 HintIC 7404 is a NOT gate IC135). What is the standard form of HTL? High Threshold Logic High Transistor Logic High Transition Logic None of the above HintThe standard form of HTL is High Threshold Logic136). __________ is the representation of decimal number 255 in binary format 10101010 10111111 11111111 None of the above Hint11111111 is the representation of decimal number 255 in binary format137). How many bits does the 11001010 binary number system have? 2 bits 4 bits 8 bits 10 bits HintThe binary number system 11001010 have 8 bits138). Which one is a NAND gate IC? 7408 7432 7404 7400 HintIC 7400 is a NAND gate IC139). How many bits does the 101011 binary number system have? 2 bits 4 bits 8 bits 6 bits HintThe binary number system 101011have 6 bits140). How many inputs does AND have? Only one Only two Only three One or N inputs HintAND gate has one or N inputs141). How many digits does the binary number system have? 2 4 8 6 HintThe binary number system has two digits are one and zero142). How many inputs does XOR gate have? Only one Only two Only three One or N inputs HintXOR gate has only two inputs143). How many inputs does NOT gate have? Only one Only two Only three One or N inputs HintNOT gate has only one input144). In the XNOR gate the output is low when the inputs are ______ Same Opposite HintIn the XNOR gate, the output is low when the inputs are opposite145). When both the inputs are low in the OR gate the output is _____ High Low HintWhen both the inputs are low in the OR gate the output is also low146). Which one is an EX-OR gate IC? 7408 7486 7404 7400 HintIC 7486 is an EX-OR gate IC147). When one of the input is high in the OR gate then the output is _____ High Low HintWhen one of the input is high in the OR gate then the output is high148). Which gate is also an inverter gate? NAND NOT AND OR HintOR gate is also an inverter gate149). _______ gate represents multiplication operation NAND NOT AND OR HintAND gate represents multiplication operation150). _______ gate represents the complement of the input NAND NOT AND OR HintNOT gate represents the complement of the input Time is Up! Time's up