Digital Logic Interview Questions/Answers YASH PAL, 19 March 202228 June 2025 In this article, we are going to see basic to advanced Digital Logic Interview Questions and Answers. digital logic basically deals with how we can represent the numerical value of quantities like analog and digital.Digital systems are the systems whichdeal with digital information in the external worlduse analog signalsmanipulate informationhandle information in digital form internallyAnswer – (4) handle information in digital form internallyAnalog systems are different from digital systems becausethey use transistorsthey handle information in analog formthey handle information in digital formthey are slowAnswer – (2) they handle information in analog formWhy are digital circuits easier to design than analog circuits?They do not control electricity precisely over a wide range.They are made in the form of ICs.All elements of digital circuits are from the same family.They are smaller in size.Answer – (1) They do not control electricity precisely over a wide range A digital gate can respond to an input signal inabout a secondabout a hundredth of a seconda few billionths of a seconda few millisecondsAnswer – (3) a few billionths of a secondAnalog methods are not used for handling extremely precise information becauseprecise information always involves numbers which are inherently digitalthere are limits to how closely an analog signal can reproduce the informationanalog information never needs to be precisethey are very expensiveAnswer – (2) there are limits to how closely an analog signal can reproduce the information Which of the following is the first integrated logic family?RTLDTLTTLMOSAnswer – (1) RTLThe time required for a pulse to change from 10 to 90 percent of its maximum value is defined asrise timedecay timepropagation tieoperating speedAnswer – (1) rise timeThe main advantages of CMOS as compared to TTL arelower power consumption and better noise marginslower power consumption with low fanouthigher speed operation with low power consumptionhigher power consumption with high fanoutAnswer – (1) lower power consumption and better noise marginsStandard TTL has a multiple-emitter input transistor and an outputtotem-polechipbipolarloading-pointAnswer – (1) totem-poleWhich of the following boolean algebra statements represent distributive law(A + B) + C = A + (B + C)A . (B + C) = (A . B) + (A . C)A . (B . C) = (A . B) . CNone of theseAnswer – (2) A . (B + C) = (A . B) + (A . C)Which of the following boolean algebra statements represent commutative law(A + B) + C = A(B + C)A . (B + C) = (A . B) + (A . C)A + B = B + AA + A = AAnswer – (3) A + B = B + AWhich of the following logic expression is incorrect?1 ⊕ 0 = 11 ⊕ 1 ⊕ 0 = 11 ⊕ 1 ⊕ 1 = 11 ⊕ 1 = 0Answer – (2) 1 ⊕ 1 ⊕ 0 = 1Let X and Y be the input and Z be the output of an AND gate. The value of Z is given byX + YX . YX . YX . YAnswer – (2) X . YWhat logic gate is represented by the circuit shown belowNANDNORANDEQUIVALENCEAnswer – (3) ANDThe boolean expression A + BC equals(A + B) (A + C)(A + B) (A + C)(A + B) (A + C)none of theseAnswer – (2) (A + B) (A + C)The clock signals are used in sequential logic circuits totell the time of the daytell how much time has elapsed since the system was turned oncarry serial data signalssynchronize events in various parts of the systemAnswer – (4) synchronize events in various parts of the systemA positive AND gate is also a negativeNAND gateNOR gateAND gateOR gateAnswer – (2) NOR gateThe term product-of-sum in Boolean algebra meansAND function of several OR functionsOR function of several AND functionsOR function of several OR functionsAND function of several AND functionsAnswer – (1) AND functions of several OR functionsAn n-stage ripple counter can count up to2^n2^n – 1n2^(n-1)Answer – (2) 2^n – 1A 2 MHZ signal is applied to the input of a J-K flip-flop which is operating in the toggle mode. the frequency of the signal at the output will be1 MHZ2 MHZ4 MHZ8 MHZAnswer – (1) 1 MHZNon-volatility is an important advantage ofCCD’sRAMPROMEPROMAnswer – (3) PROMNote – More questions and answers related to the interview will be added from time to time. Computer Science Tutorials Digital Logic Tutorials Interview questions answers computer scienceinterview preparation