Flip Flops Question & AnswersMay 18, 2021 By WatElectronics This article lists 100 Flip Flop MCQs for engineering students. All the Flip Flop Questions & Answers given below includes solution and link wherever possible to the relevant topic.In a sequential circuit design, flip-flops are the basic building blocks. In a short or in a very simple way we can say that flip flop is on and off. The sequential circuit is generally a combinational circuit with memory. The flip flop stores only binary data that has two states are logic 1 and logic 0. The set-reset, JK, delay, and trigger or toggle are the most commonly used flip flops. The multiplexer is an example of a combinational circuit and the flip flop is an example of a sequential circuit. The combinational circuit doesn’t have a memory unit whereas the sequential circuit has a memory unit.The first flip flop was invented by F.W.Jordan and William Eccles. The Delay flip flop converts into other flip flops in three ways they are D to JK, T, and SR flip flop. The type of operation performed by flip flops is synchronous and the type of operation performed by latches is asynchronous. The flip flops require more area and more power compared to latches. The toggle or trigger flip flop convert to other flip flops in three ways they are T to JK, SR, and D flip flop. The flip-flops store only one bit of information. The required flip flop in T to D flip flop conversion is D flip flop, and the required flip flop in JK to D flip flop conversion is D flip flop.1). The output of the sequential circuit depends upon _________ Present input Past input Present input and present state None of the above HintThe output of the sequential circuit depends upon present input and present state (past output)2). The flip flops are categorized into ________ One Two Three Four HintThe flip flops are categorized into four types they are set-reset, trigger or toggle, delay, and J-K flip flop3). What is the standard form of S-R flip flop? Set Reset Simple-Reset Single-Reset None of the above HintThe standard form of S-R flip flop is a set-reset flip flop4). When the set is enabled in S-R flip flop then the output will be __________ Set Reset No change Indeterminate HintWhen the set is enabled in S-R flip flop then the output will be set means one5). When the set is disabled and reset is enabled in S-R flip flop then the output will be __________ Set Reset No change Indeterminate HintWhen the set is disabled and reset is enabled in S-R flip flop then the output will be reset means zero6). When both set and reset are disabled in S-R flip flop then the output will be __________ Set Reset No change Indeterminate HintWhen set and reset neither them are enabled then there will be no change means the previous output will be the present output7). When both set and reset are enabled in S-R flip flop then the output will be __________ Set Reset No change Indeterminate HintWhen both set and reset are enabled in S-R flip flop then the output will be in Indeterminate condition that is known as a race condition8). In which flip flop the present input will be the next output? S-R J-K D T HintIn D-flip flop the present input will be the next output9). The J-K flip flops has ___________ memory Temporary Random Nonrandom True HintThe J-K flip flops have a true memory10). The preset input is used to make output ______ Q=1 Q=0 Invalid No change HintThe preset input is used to make output Q=111). The clear input is used to make output ______ Q=1 Q=0 Invalid No change HintThe clear input is used to make output Q=012). The preset and clear inputs don’t need synchronization? True False HintYes, the preset and clear inputs both doesn’t need synchronization13). When preset=0, clear=1 then the output will be ________ One Zero Not used FF operation HintWhen preset=0, clear=1 then the output will be one14). When preset=1, clear=0 then the output will be ________ One Zero Not used FF operation HintWhen preset=1, clear=0 then the output will be zero15). There are total ______ steps for flip flop conversions One Two Three Five HintThere are total of five steps for flip flop conversions they are not available required flip flop, write characteristics table of required F/F, write excitation table of available F/F, solve Boolean expression and draw circuit16). In SR to JK flip flop conversion which one is an available flip flop? SR JK T Both SR and JK HintIn SR to JK flip flop conversion, SR flip flop is an available flip flop17). In SR to JK flip flop conversion which one is a required flip flop? SR JK T Both SR and JK HintIn SR to JK flip flop conversion JK flip flop is required flip flop18). The shift registers are categorized into ________ One Two Three Four HintThe shift registers are categorized into four types they are SISO, PIPO, SIPO, and PISO19). How many possible conversions are there to convert SR flip flop to other flip flops? One Two Three Four HintThe SR flip flop convert into other flip flops in three ways they are SR to JK, T, and D flip flop20). A flip flop is an __________ Edge sensitive device Synchronous device Both a and b None of the above HintA flip flop is an edge-sensitive and synchronous device21). The operation of the flip flop is slow? True False HintYes, the operation of the flip flops are very slow compared to latches that are only due to the clock signal22). How many types of latches are there? One Two Six Four HintThere are six types of latches are there they are SR, gated SR, D, gated D, JK, and T latch23). The flip flop requires _________ More number of gates More power Both a and b None of the above HintThe flip flop requires more gates and power when compared to latches24). _________ are the applications of flip flop Registers Counters Storage devices All of the above HintThe registers, counters, storage devices, frequency dividers, etc are the applications of flip flop25). Does the flip flop based on enable function input? True False HintNo, the flip flops don’t base on enabling function input it based on clock pulsesFlip-Flops Important Questions with Hints26). The flip flops works with ________ Binary inputs Clock signal Both a and b None of the above HintThe flip flop works with both clock signal and binary inputs27). The flip flop can’t be used as a register is it true? True False HintNo, the flip flops can be used as a register28). What is the standard form of T flip flop? Trigger Toggle Trigger or toggled None of the above HintThe standard form of T flip flop is a trigger or toggle flip flop29). The JK flip flop convert to other flip flops in ________? One-way Two ways Three ways Four ways HintThe JK flip flop convert into other flip flops in three ways they are JK to SR, T, and D flip flop30). How many types of triggers are there? One type Two types Three types Four types HintThere are three types of triggers are there they are edge, level, and pulse triggering31). When S=0, R=0, CLK=X then the output will be ___________ No change Set Reset Invalid HintWhen S=0, R=0, CLK=X then there will be no change in the output 32). When reset is low and set is high in a NOR D-latch table then the output will be __________ No change High Low Invalid HintWhen reset is low and set is high in a NOR D-latch table then the output will be high33). When reset is high and set is low in a NOR D-latch table then the output will be __________ No change High Low Invalid HintWhen reset is high and set is low in a NOR D-latch table then the output will be low34). When reset is high and set is low in a NAND D-latch table then the output will be __________ No change High Low Invalid HintWhen reset is high and the set is low in a NAND D-latch table then the output will be low35). When reset is low and set is high in a NAND D-latch table then the output will be __________ No change High Low Invalid HintWhen reset is low and the set is high in a NAND D-latch table then the output will be high36). Which circuit doesn’t have a memory unit? Combinational Sequential Both a and b None of the above HintThe combinational circuit doesn’t have a memory unit whereas the sequential circuit has a memory unit37). ________ is an example for sequential circuit Flip flop Full adder Half adder None of the above HintThe flip flop is an example of a sequential circuit38). _______ is an example for combinational circuit Flip flop Register Multiplexer None of the above HintThe multiplexer is an example of a combinational circuit39). How many possible conversions are there to convert T flip flop to other flip flops? One way Two ways Three ways Four ways HintThe toggle or trigger flip flop convert to other flip flops in three ways they are T to JK, SR, and D flip flop40). What is the standard form of D flip flop? Data Deterministic Delay None of the above HintThe standard form of D flip flop is delay flip flop41). How many inputs does the RS latch have? One input Two inputs Three inputs Four inputs HintThe RS latch has two inputs they are set and reset42). When triggers on high clock level then this type of trigger is known as ________ High level Low level Positive level Negative level HintWhen triggers on high clock level then this type of trigger is known as high-level triggering43). When triggers on low clock level then this type of trigger is known as ________ High level Low level Positive level Negative level HintWhen triggers on low clock level then this type of trigger is known as low-level triggering44). The flip flops require ________ More power More area Less power Both a and b HintThe flip flops require more area and more power compare to latches45). The type of operation performed by flip flop is _______ Synchronous Asynchronous Both a and b None of the above HintThe type of operation performed by flip flop is synchronous46). The type of operation performed by latches is _______ Synchronous Asynchronous Both a and b None of the above HintThe type of operation performed by latches is asynchronous47). The flip flop is a _______ device Unstable Bi-stable Both a and b None of the above HintThe flip flop is a bi-stable device that is used to store either o or 148). In which year the first flip flop was invented? 1915 1916 1917 1918 HintIn 1918 the first flip flop was invented49). How many possible conversions are there to convert D flip flop to other flip flops? One-way Two ways Three ways Four ways HintThe Delay flip flop convert into other flip flops in three ways they are D to JK, T, and SR flip flop50). Who invented first flip flop? F.W.Jordan William Eccles Harald Both a and b HintThe first flip flop was invented by F.W.Jordan and William Eccles Read more about FlipflopsFlip-Flops Important Questions for Engineering Students51). The set-reset flip flops constructed by cross-coupling of ______ gates AND or NAND NAND or NOR XNOR or NOR None of the above HintThe set-reset flip flops constructed by cross-coupling of NAND or NOR gates52). The sequential circuits are categorized into _______ One Two Three Four HintThe sequential circuits are categorized into two types they are synchronous and asynchronous sequential circuits53). How many inverters does the basic latch consists of? One Two Three Four HintThe basic latch consists of two inverters54). How many additional AND gates does SR flip flop consists of? One Two Three Four HintThe set-reset flip flop consists of two AND gates at the set and resets inputs of the S-R latch55). The J-K flip flop characteristic similar to _________ flip flop D flip flop T flip flop S-R flip flop None of the above HintThe J-K flip flop characteristic similar to set-reset flip flop56). The latch is a __________ device Unstable Bistable Both a and b None of the above HintThe latch is a bi-stable device that is used to store either o or 157). When toggle condition occurs in JK flip flop? J=1, K=1 J=0, K=0 J=1, K=0 J=0, K=1 HintWhen both J and K inputs are high then their toggle condition occurs 58). The no-change conditions occur when ________ in JK flip flop J=1, K=1 J=0, K=0 J=1, K=0 J=0, K=1 HintThe no-change condition occurs when J=0, K=0 in JK flip flop59). The flip flop are categorized into _______ types One Two Three Four HintThe flip flop is categorized into four types they are SR, D, JK, and T flip flops60). How many outputs does D-flip flop have? One Two Three Four HintThe D-flip flop has only one output61). When the clock input is low in a D flip flop then the input of the D flip flop is _______ High Low No effect None of the above HintWhen the clock input is low in a D flip flop then there is no change in the delay input62). When the clock input is high and D input is high then the output of a D flip flop will be _______ High Low No effect None of the above HintWhen the clock input is high and D input is high then the output of a D flip flop will be low63). The combinational circuit have ____________ number of stable states One Two Three Four HintThe combinational circuit has two stable states they are zero and one64). How many inputs does D flip flop have? One Two Three Four HintThe D flip flop has only one input65). The flip flops are activated by _____________ trigger Only positive edge Only negative edge Either positive or negative edge None of the above HintThe flip flops are activated by either positive or negative edge trigger66). The RS flip flop input clock is given to _______ Output Input Both a and b Pulse HintThe RS flip flop input clock is given to pulse67). How many NAND gates does the D flip flop circuit consists of? One Two Three Four HintThe D flip flop circuit consists of four NAND gates68). The inputs of the SR, JK, and D flip flop are the _____ inputs Bidirectional Unidirectional Synchronous Asynchronous HintThe inputs of the SR, JK, and D flip flop are the synchronous inputs Read more about Gates69). The counters are categorized into ______ One Two Three Four HintThe counters are categorized into three types they are asynchronous/synchronous modulus, and single & multimode 70). How many states does the decimal counter have? One Ten Three Four HintThe decimal counter has ten states71). The synchronous counter is one type of _______ counter SSI LSI VLSI MSI HintThe synchronous counter is one type of medium-scale integrated counter72). The BCD is one type of counter which is also known as __________ Synchronous Asynchronous Parallel Decade HintThe BCD is one type of counter which is also known as a decade counter73). The counter circuit parallel outputs represent _________ Clock count Serial data word Parallel data word None of the above HintThe counter circuit parallel outputs represent clock count74). How many of states are there in a 4 bit counter? One Four Eight Sixteen HintThe number of states in a four-bit counter is 1675). An IC 7493 is a______ bit binary ripple counter One Four Eight Sixteen HintAn IC 7493 is a four-bit binary ripple counterFlip-Flops Important Questions for Interviews76). How many JK master-slave flip flops are required for IC 7493? One Four Eight Sixteen HintIC 7493 required four JK master-slave flip flops 77). Which IC is a decade counter? IC 7490 IC 7491 IC 7492 IC 7493 HintAn IC 7490 is a decade counter78). How many pins does ripple counter IC have? 4 8 12 14 HintThe ripple counter IC has 14 pins Read more about Counters79). __________ type of counter counts in an upward manner Up counter Down counter Decade counter None of the above HintThe up counter is a type of counter which counts in an upward manner80). In which manner does down counter count? Upward Downward Both a and b None of the above HintThe down counter counts in a downward manner81). The high-speed counter is a __________ type of counter Decade counter Synchronous counter Asynchronous counter None of the above HintThe high-speed counter is a synchronous type of counter82). The another name for fundamental mode is ____________ Clock Edge Pulse None of the above HintThe other name for fundamental mode is pulse operation83). Is it true that the up-down counter is a combination of latches and flip-flops? True False HintNo, the up-down counter is a combination of latches and flip flops, it is a combination of up and down counter84). How many of states are there in a 3 bit counter? One Four Eight Sixteen HintThe number of states in a three-bit counter is 885). Which one is also called as a multimode counter? Decade counter Synchronous counter Asynchronous counter Up and down counter HintThe up and down counter is also called a multimode counter86). __________ is a truncated modulus example Modulus-9 Modulus-15 Modulus-11 All of the above HintModulus-9, 11, and 15 is a truncated modulus example87). Is register is a type of combinational circuit? True False HintNo, the register is not a type of combinational circuit, it’s a type of sequential circuit88). What is the standard form of SISO? Serial Input Serial Output Serial Output Serial Input Simple Input Serial Output None of the above HintThe standard form of SISO is Serial Input Serial Output89).What is the standard form of PIPO? Parallel Input Parallel Output Parallel Output Serial Input Simple Input Serial Output None of the above HintThe standard form of PIPO is Parallel Input Parallel Output90). The Johnson and ring shift counters are _________ type of counters Binary Synchronous Asynchronous None of the above HintThe Johnson and ring shift counters are the synchronous type of counters91). Does an IC 74HC195 use for all SISO, PIPO, SIPO, and PISO operations? True False HintYes, an IC 74HC195 used for all SISO, PIPO, SIPO, and PISO operations92). How many bits of information do flip-flop store? One-bit Ten-bit Two-bit Three-bit HintThe flip flops store only one bit of information93). The very large scale integration chip is made up of _______ BICMOS, CMOS BJT, NMOS Both a and b None of the above HintThe very large scale integration chip is made up of BICMOS, CMOS, BJT, and NMOS94). How many of states are there in a 2 bit counter? One Four Eight Sixteen HintThe number of states in a two-bit counter is 495). What is the standard form of SOSI? Serial Input Serial Output Serial Output Serial Input Simple Input Serial Output None of the above HintThe standard form of SOSI is Serial Output Serial Input96).What is the standard form of POSI? Serial Input Serial Output Parallel Output Serial Input Simple Input Serial Output None of the above HintThe standard form of POSI is Parallel Output Serial Input97). Read-only memory consists of _______ arrays OR array NAND array Both a and b None of the above HintRead-only memory consists of both NAND and OR arrays98). What is the available flip flop in T to D flip flop conversion? D flip flop T flip flop S-R flip flop None of the above HintThe available flip flop in T to D flip flop conversion is T flip flop99). What is the required flip flop in T to D flip flop conversion? D flip flop T flip flop S-R flip flop None of the above HintThe required flip flop in T to D flip flop conversion is D flip flop100). What is the required flip flop in JK to D flip flop conversion? D flip flop T flip flop S-R flip flop None of the above HintThe required flip flop in JK to D flip flop conversion is D flip flop Time is Up! Time's up
