Logic Gates Question & Answers June 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 athematic 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 Hint 2). _______ are basic gates NOT NAND AND NOT, AND, & OR Hint 3). __________ are universal gates NOT NAND & NOR AND NOT, AND, & OR Hint 4). __________ are arithmetic gates NOT NAND & NOR X-OR & X-NOR NOT, AND, & OR Hint 5). _________ are the common forms of complex logic gates OR-AND-Invert (OAI) AND-OR-Invert (AOI) Both OAI and AOI None of the above Hint 6). 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 7). What are the advantages of static complementary gates? Reliable Not easy to use Not reliable Reliable and easy to use Hint 8). Who invented Boolean algebra? Bardeen Claude Shannon George Boole None of the above Hint 9). How many terminals do MOS transistors have? One b) c) d) Two Three Four Hint 10). _________ are the alternative form of canonical form Sum of products Product of sums Both a and b None of the above Hint 11). The sum of products canonical forms also known as ________ Minterm expansion Disjunctive normal form Both a and b None of the above Hint 12). The product of sums canonical forms also known as ________ Maxterm expansion Conjunctive normal form Both a and b None of the above Hint 13). ______ 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 14). ______ is an example of dominance law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hint 15). ______ is an example of commutativity law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hint 16). ______ is an example of associativity law a+0=0+a=a 1+a=a+1=1 ab=ba a+(b+c)=(a+b)+c Hint 17). ______ 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 Hint 18). Combinational logic is used to ___________ Compute outputs Compute new states Both a and b None of the above Hint 19). The sequential logic contains ___________ Memory elements Memory is provided by feedback Both a and b None of the above Hint 20). _________ are the methods used to represent negative integer numbers 1’s compliment Sign magnitude 2’s compliment All of the above Hint 21). How many types of number systems are there? One Two Three Four Hint 22). The base is 16 for _______ number system Binary Hexadecimal Decimal Octal Hint 23). The American standard code for information interchange has _____ characters 64 25 128 None of the above Hint 24). 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 Hint 25). How many types of parities are there? One Two Three Four Hint Logic Gate MCQs for Quiz 26). The ones complement of binary number 1010 is ___________ 0101 1010 0110 1110 Hint 27). The 2’s complement of binary number 1010 is ___________ 0101 1010 0110 1110 Hint 28). The base is eight for _______ number system Binary Hexadecimal Decimal Octal Hint 29). How many types of IC packages are there? One Two Three Four Hint 30). IC’s are categorized into ____________ One Two Three Four Hint 31). How many gates does ultra large scale integration contain? 100 gates 1000 gates 10000 gates More than 100,000 gates Hint 32). How many gates does very large-scale integration contain? 100 gates 10,000 to 100,000 gates 10000 gates None of the above Hint 33). 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 34). 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 Hint 35). 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 Hint 36). The base is ten for _______ number system Binary Hexadecimal Decimal Octal Hint 37). The base is two for _______ number system Binary Hexadecimal Decimal Octal Hint 38). What are the advantages of ICs? Small in size Low-cost Operating speed is high All of the above Hint 39). Which IC is a quad two-input NAND gate? 74LS00 74LS01 74LS03 All of the above Hint 40). The supply voltage of the 7400 series TTL family IC’s is __________ 1V 2V 4V 5V Hint 41). What is the standard form of TTL? Transistor-Transistor Logic Transistor Transducer Logic Transducer Transistor Logic None of the above Hint 42). The voltage range of low power Schottky is ________ 1V 2V 4V 5V Hint 43).The maximum toggle speed of the 7400 TTL family ICs is _____ 20MHz 10 MHz 15 MHz 25 MHz Hint 44). The speed of the low power Schottky is _____ 2ns 8ns 10ns 12ns Hint 45). The power of the low power Schottky is _____ 1mW 2mW 4mW None of the above Hint 46). The voltage range of advanced low power Schottky is _____ 1V 2V 4V 5V Hint 47). The speed of the advanced low power Schottky is _____ 2ns 7ns 10ns 12ns Hint 48). The power of the advanced low power Schottky is _____ 1mW 2mW 4mW None of the above Hint 49). The maximum input current of the silicon gate CMOS is ______ 0.1mA 0.5mA ±0.0001mA None of the above Hint 50). The maximum clock of silicon gate CMOS is ______ 20MHz 40 MHz 15 MHz 25 MHz Hint Logic Gate MCQs for Interviews 51). The propagation time delay of the silicon gate CMOS is _____ 2ns 7ns 10ns 8ns Hint 52). Which IC is quad two-input AND gate? 74LS08 74LS00 74LS01 All of the above Hint 53). The maximum input current of the metal gate CMOS is _________ 0.0001mA -0.0001mA c ±0.0001mA None of the above Hint 54). The maximum clock of the metal gate CMOS is _________ 20MHz 40 MHz 12 MHz 25 MHz Hint 55). The propagation delay of the metal gate CMOS is ________ 2ns 7ns 10ns 105ns Hint 56). How many types of logic families are there? Two Four Six Seven Hint 57).What is the standard form of IIL? Injection Integrated Logic Integrated Injection Logic Integrated Integrated Logic None of the above Hint 58). The noise immunity is excellent in _____ logic family CMOS TTL ECL None of the above Hint 59). The maximum input current of the Schottky TTL gates is _________ -2.0mA 2.0mA -2.5mA -1.0mA Hint 60). The maximum clock of low power Schottky TTL is __________ 20MHz 40 MHz 12 MHz 25 MHz Hint 61). The propagation delay of the low power Schottky TTL is __________ 2ns 7ns 10ns 105ns Hint 62). The fanout of the CMOS logic family is ______ >10 >20 >30 >50 Hint 63). What are the components used in the RTL logic family? Resistors Transistors Both a and b None of the above Hint 64). The TTL family is classified into __________ Two Four Six Seven Hint 65). Which IC is a quad two-input NOR gate? 74LS02 74LS01 74LS00 None of the above Hint 66). The maximum input current of the low power Schottky TTL is ____________ 0.2mA 0.3mA -0.4mA 0.1mA Hint 67). The maximum clock of Schottky TTL gate is __________ 20MHz 40 MHz 12 MHz 125 MHz Hint 68). The propagation delay of Schottky TTL gate is ________ 3ns 7ns 10ns 105ns Hint 69). The noise immunity is very good in _____ logic family CMOS TTL ECL None of the above Hint 70). The fan-out of TTL logic family is __________ 2 5 8 10 Hint 71). What are the components used in the DCTL logic family? Resistors transistors Diodes Both a and b Hint 72). Which IC is a triple three-input AND gate? 74LS11 74LS10 74LS12 None of the above Hint 73). The maximum input current of the advanced low power Schottky TTL gate is ________ 0.2mA 0.3mA -0.4mA -0.1mA Hint 74). The maximum clock of advanced low power Schottky TTL is __________ 70MHz 40 MHz 12 MHz 25 MHz Hint 75). The propagation delay of advanced low power Schottky TTL gate is ________ 3ns 4ns 10ns 105ns Hint 76). What are the components used in the TTL logic family? Resistors, Transistors Diodes Both a and b None of the above Hint Logic Gate MCQs for Exams 77). The RTL logic family has ______ Poor noise margin Poor fan-out Higher speed and power dissipation All of the above Hint 78).Which IC is a triple three-input NAND gate? 74LS11 74LS10 74LS27 None of the above Hint 79). The maximum input current of the advanced Schottky TTL gate is _______ 0.2mA 0.3mA -0.5mA -0.1mA Hint 80). The maximum clock of advanced low power Schottky TTL is __________ 200MHz 40 MHz 12 MHz 25 MHz Hint 81). The propagation delay of advanced Schottky TTL gate is ________ 3ns 1.5ns 10ns 105ns Hint 82). The noise immunity is good in _____ logic family CMOS TTL ECL None of the above Hint 83). The fan-out of the ECL logic family is ________ 10 20 25 None of the above Hint 84). What are the components used in the DTL logic family? Resistors Diodes Transistors All of the above Hint 85). Which IC is a triple three-input NOR gate? 74LS10 74LS11 74LS27 All of the above Hint 86). What are the components used in the ECL logic family? Resistors Transistors Both a and b None of the above Hint 87). The DTL logic family has _________ Improved noise margin and fan-out Low speed Both a and b None of the above Hint 88). The power dissipation in RTL logic family is ______ 30mv 40mv 50mv 60mv Hint 89). In which logic family the power dissipation is very low? RTL DCTL CMOS TTL Hint 90). Which IC is a dual four-input NAND gate? 74LS20 74LS21 74LS27 None of the above Hint 91). What are the components used in COS logic family? PMOS NMOS Both a and b None of the above Hint 92). The power dissipation in the DTL logic family is ________ 1-12mv 4-12mv 6-12mv 8-12mv Hint 93). How many types of logic families are there? One Two Three Four Hint 94). Which one is a saturated bipolar logic family? RTL Schottky TTL ECL None of the above Hint 95). Which one is an unsaturated bipolar logic family? RTL Schottky TTL DTL None of the above Hint 96). Which IC is a dual four-input AND gate? 74LS13 74LS20 74LS21 None of the above Hint 97). The power dissipation in the ECL logic family is ______ 30mv 40-55mv 50-80mv 60-90mv Hint 98). Which one belongs to the unipolar logic family? RTL, DCTL, DTL TTL, ECL CMOS, PMOS, NMOS None of the above Hint 99). The basic gate of the TTL logic family is _____ NAND NOT NOR None of the above Hint 100). The basic gate of the ECL logic family is _____ NAND NOT OR/ NOR None of the above Hint Logic Gate Important MCQs with Hints 101). The basic gate of the CMOS logic family is _____ NAND NOT NAND/ NOR None of the above Hint 102). The noise immunity of TTL logic family is _________ Strong Good Very strong Poor Hint 103). Which IC is a hex NOT gate? 74LS04 74LS19 74LS23 None of the above Hint 104). The power dissipation of TTL logic family is ____________ 30mv 40mv 10mv 60mv Hint 105). The noise margin in TTL logic family is _______ Moderate Low High None of the above Hint 106). 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 Hint 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 1.75mv None of the above Hint 108). For ECL logic family the logic high voltage is about ______ -1.5v 1.80mv 1.75mv 0.8v Hint 109). The noise margin in the ECL logic family is _______ Moderate Low High None of the above Hint 110). The noise immunity of the ECL logic family is _________ Strong Good Very strong Poor Hint 111). IC 74LS belongs to _________logic family Low power Schottky TTL Fast power Schottky TTL Advanced Schottky TTL Advanced low power Schottky TTL Hint 112). 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 Hint 113). 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 Hint Read more about Digital Circuits 114). 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 Hint 115). The noise immunity of the CMOS logic family is _________ Strong Good Very strong Poor Hint 116). The noise margin in CMOS logic family is _______ Moderate Low High None of the above Hint 117). __________ are the delay of the signal transition from input to output Propagation delay Threshold voltage Power dissipation None of the above Hint 118). _______ explains how much power dissipated on the integrated chip Propagation delay Threshold voltage Power dissipation None of the above Hint 119). ________ is the multiplication of propagation delay and power dissipation Propagation delay Threshold voltage Power dissipation Figure of merit Hint 120). ________ explains how many similar gates can be driven by a given logical gate Fan-in Fan-out Power dissipation Figure of merit Hint Logic Gate MCQs for Engineers 121). ________ explains how many inputs can be there with a given logical gate Fan-in Fan-out Power dissipation Figure of merit Hint 122). In IC’s the propagation delay is measured in terms of _______ ns mv MHz None of the above Hint 123). ________ 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 Hint 124). _______ is the Boolean expression of AND logic gate X=A+B X=A-B X=AB None of the above Hint 125). _______ is the Boolean expression of OR logic gate X=A+B X=A-B X=AB None of the above Hint Read more about Logic Gates 126). Which one is a AND gate IC? 7408 7432 7404 7400 Hint 127). The basic gate of the HTL logic family is _______ NAND NOR OR NOT Hint 128). 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 Hint 129). The fan-out of integrated injection logic is _________ 8 5 Depends on injector current None of the above Hint 130). What are the limitations of the RTL? Low speed High power consumption Operating speed is <4MHz All of the above Hint 131). Which one is an OR gate IC? 7408 7432 7404 7400 Hint 132). The low power TTL is introduced in __________ 1989 1964 1990 2000 Hint 133). What is the standard form of DCTL? Diode Coupled Transistor Logic Direct Coupled Transistor Logic Diode Coupled Logic None of the above Hint 134). Which one is a NOT gate IC? 7408 7432 7404 7400 Hint 135). What is the standard form of HTL? High Threshold Logic High Transistor Logic High Transition Logic None of the above Hint 136). __________ is the representation of decimal number 255 in binary format 10101010 10111111 11111111 None of the above Hint 137). How many bits does the 11001010 binary number system have? 2 bits 4 bits 8 bits 10 bits Hint 138). Which one is a NAND gate IC? 7408 7432 7404 7400 Hint 139). How many bits does the 101011 binary number system have? 2 bits 4 bits 8 bits 6 bits Hint 140). How many inputs does AND have? Only one Only two Only three One or N inputs Hint 141). How many digits does the binary number system have? 2 4 8 6 Hint 142). How many inputs does XOR gate have? Only one Only two Only three One or N inputs Hint 143). How many inputs does NOT gate have? Only one Only two Only three One or N inputs Hint 144). In the XNOR gate the output is low when the inputs are ______ Same Opposite Hint 145). When both the inputs are low in the OR gate the output is _____ High Low Hint 146). Which one is an EX-OR gate IC? 7408 7486 7404 7400 Hint 147). When one of the input is high in the OR gate then the output is _____ High Low Hint 148). Which gate is also an inverter gate? NAND NOT AND OR Hint 149). _______ gate represents multiplication operation NAND NOT AND OR Hint 150). _______ gate represents the complement of the input NAND NOT AND OR Hint Time is Up! Time's up