Multivibrator Question & AnswersAugust 4, 2021 By WatElectronics This article lists 100 Multivibrator MCQs for engineering students. All the Multivibrator Questions & Answers given below includes solution and link wherever possible to the relevant topic.A sequential logic circuit utilized in building up complex circuitry can be a Counter, Latch, and Memories. These circuits must be provided with a timing or clock signal to make them function sequentially. This type of Single Pulse Generator circuit is known as a Multivibrator. Multivibrators are available in three types like astable, monostable, and bistable. The astable multivibrator has no stable states, so it switches continually from one condition to the other. So, it works like a relaxation oscillator.In a monostable multivibrator, one of the states is stable whereas the other state is not stable. As the name suggests, a bistable multivibrator includes two stable states. Here, a separate trigger signal is necessary from one stable state to another stable state for the transition. The applications of multivibrators mainly include; these can be used as saw tooth generators, frequency generators, pulse, and wave generators, used in tv and radar circuits, etc.1). Multivibrators are also referred to as ______. Linear oscillators Non-linear oscillators Function generators b and c HintElectronic circuit that can generate rectangular, pulse and square waveforms2). Which feedback does a multivibrator have? Positive and Negative Only Negative Regenerative Degenerative HintTwo circuits of amplifiers3). What are the types of Multivibrators? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator All the above HintPresence of Stable states multivibrators are classified into three types4). Astable Multivibrators has ________ Stable states. Zero One Two Three HintNo Stable states5). Which multivibrators consist of One Stable state? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Tristable Multivibrator HintMonostable multivibrators require external triggering6). What type of Multivibrator can produce only one Single pulse? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Data insufficient HintEither positive or negative pulse7). How many states does a Bistable Multivibrator possess? Zero One Two Three HintBistable multivibrators generate either a negative or the positive value pulse8). What do you mean by Quasi stable? Permanent stable Temporary stable Steady state Can’t say HintTemporary state of stability9). What are the elements used for coupling in Bistable Multivibrators? Resistors Capacitors Inductors Diodes HintDc coupling10). What type of multivibrator needs triggering for Reverse transition? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Pulse Generator HintTransition of one stable state to another11). Astable multivibrators can function as ______________. Linear oscillators Relaxation oscillators Non-Relaxation oscillators a & c HintAstable multivibrators are unable to maintain stability in any of the states and continue to switch12). Which Multivibrator is known as Flip-flop Multivibrator? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Pulse Generator HintFlip-flops13). What are the other names of Bistable multivibrators? Flip-flop Binary Trigger circuit All mentioned earlier HintFlip-flops possess two ‘stable’ states14). Monostable multivibrator is also known as ___________. One shot Monoflop Flip-flop Both a and b HintNo output is produced until it is triggered15). Why the Monostable Multivibrator referred to as Delay circuit? Transition time is predetermined No need of transition Transition is slow Data insufficient HintThe time-lapse required for the transition of a Quasi-stable state to a Stable state is pre-determined16). Bistable Multivibrators is known as _________. One shot Mono flop Relaxation Oscillator Binary HintTwo states are stable in Bistable multivibrators17). How do Multivibrators differ from Oscillators? Produces one waveform as outcome Generates rectangular, square, and pulse waves as outcomes Produces sine wave as output Same HintType of waveform produced18). Why a Flip-flop Multivibrator is termed as Two-shot Multivibrator? One state is stable Two states are stable Three states are stable Four states are stable HintTwo-shot Multivibrator19). How many trigger pulses required for Bistable multivibrators? One Two Three Four HintTwo pulses are required for triggering20). Which of these multivibrator produces square wave as the outcome? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Triggered Oscillator HintSquare wave generator21). Duty cycle of an Astable multivibrator is ________. 30% 50% 70% 100% HintSquare pulses22). What kind of multivibrators have equal time for a capacitor to charge and discharge? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator Triggered Oscillator HintTime for the capacitor to charge and discharge is equivalent in Astable multivibrators23). How many stages of amplifier present in Astable Multivibrator? One Two Three Four HintBoth the stages of amplifiers are cross-coupled to each other24). Which is the feedback present in Astable multivibrators? Positive and Negative Only Negative Only Positive Degenerative HintPositive feedback is very strong in Astable multivibrators25). Which of the below circuit has a Quasi stable state? Bistable multivibrator Monostable multivibrator Tristable multivibrator Tetra stable multivibrator HintMonostable multivibrator has two statesMultivibrators Important Questions for Interviews26). What does a symmetrically coupled collector circuit consists of? Two transistors identical Resistors and Capacitors Both a and b Transformer HintRC coupled stages of amplifiers27). What happens to the signal when passed through Common-emitter amplifier’s first stage? Strength is reduced Decrease in frequency Reversed phase Doesn’t change HintPhase gets reversed28). Multivibrators output is collected from ___________ of any transistor. Base Emitter Collector Drain HintCollector-coupled multivibrator29). How the transistors Q1 and Q2 alternates in the multivibrator circuit? Q1 On, Q2 Off Q1 Off, Q2 Off Q1 On, Q2 On Can’t say HintOne transistor is ON the other remains in OFF30). Total time period of the Square wave is ________. 0.69 RC 1.38 RC 1.48 RC 1.68 RC HintDouble of 0.69 RC31). How the frequency can be determined for the oscillations? Reciprocate of Time period 1/ 1.38RC 1/0.69RC Both a and b HintReciprocal of the total time interval32). Which is known as Free-running Multivibrator? Astable multivibrator Monostable multivibrator Bistable multivibrator Both a and b HintAn astable circuit is capable of generating output without any need for external excitations33). How frequency at the output can be varied in Astable multivibrator circuit? Changing the resistor value Changing the capacitor value Both a and b Changing the transistors HintChange in the capacitor and the resistor34). What is the main application of a Monostable multivibrator? Oscillators Timers Flip-flops Binary HintTime interval in the Monostable circuit is set manually35). What happens to the Monostable circuit when it is triggered externally? Jump to Stable state Jump to Quasi-stable state Doesn’t change Oscillates frequently HintQuasi-stable from Stable36). Monostable circuit from state of Quasi-stable will return to Stable by _________. With an External trigger Due to Predefined time interval Without any External trigger b and c HintA monostable circuit is triggered once37). On what factor the time interval in the Multivibrator circuit depend? External trigger Resistor value Capacitor value b and c HintPassive components38). What happens to the Monostable circuit if it is not triggered externally? Both transistors are at Cut-off Both transistors in Saturation One transistor is at Cut-off, other is at saturation Both transistors are Active HintOne transistor will be at Saturation and the other at Cut-off39). What are the applications of a Monostable circuit? Timers Delay circuits Gated circuits All mentioned earlier HintTimers, Delay circuits40). The cycle to charge a capacitor is __________ than a cycle of discharge in Astable multivibrator. Faster Slower Lesser Compressed HintAstable multivibrators41). Which of these multivibrators are preferred for lower clock frequencies? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintFrequently switching characteristics Astable multivibrators42). What kind of Multivibrator have two networks of RC? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintAstable circuit has two RC networks cross-coupled43). Monostable multivibrator consists of _________. Two transistors RC and Resistive networks Absent load capacitor a, b and c HintHalf Astable multivibrator44). Which multivibrators have only Resistive coupling? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintBistable circuits of multivibrators45). Which multivibrators need external triggering to operate? Bistable multivibrator Monostable multivibrator Astable multivibrator a & b HintAutomatic triggering46). What does a Astable multivibrator comprise of? Two transistors Feedback network Delay capacitors a, b and c HintCross-coupled switching transistor circuit47). How many capacitors present in Astable circuit? Two Three Four Five HintTwo capacitors to delay time48). What kind of multivibrator preferred in Flash lights? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator Hint A square wave is generated at output continuously49). On what factors the output wave generated is dependent on? Two transistors Feedback network Delay capacitors Frequency HintRC (feedback) network50). Which is the most commonly preferred circuit of Multivibrators? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintAstable is the most simple and easy while implementingMultivibrator Question & Answers51). What can improve the switching capability in Bistable multivibrators? Resistors Capacitors Transistors Feedback HintCommutating capacitors in Bistable circuitRead More About Flip-Flops52).What reduces the time of transition in Bistable multivibrator? Resistors Capacitors Transistors Feedback HintCapacitors reduces the time required to transfer the conduction of the current53). Commutating capacitors are also referred to as ________ capacitors. Slow-Down Speed-Up Transition Slow HintReduce time in transition the processing speed gets enhanced54). What multivibrator is chosen for counting applications? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintFlip-flops used in counting applications55). Which is the costliest multivibrator? Astable multivibrator Monostable multivibrator Bistable multivibrator Can’t say HintBistable multivibrator is expensive56). What is the disadvantage of Bistable circuit? Triggering is must Store previous outcome Design is simple Direct coupling HintTriggering is required for the transition of states57). Frequency divider application uses _________. Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintBistable circuit divides the frequency at input58). Which of the multivibrator are known for repairing damaged pulses? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator Hint A monostable circuit can be used as input to the ‘Pulse Generator circuits’59). Which of the multivibrator chosen to function as Linear Ramp Generator? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintAdditional source of Constant current Monostable circuit60). Which state the Bistable circuit will be without trigger? Low High Reset Quasi HintBistable circuit stays at Low state61). What happens to the Bistable circuit at High state when the Reset is applied? Changes from Low to High Changes from High to Low Switches continuously Remains same HintBistable circuit makes it change to a Lower state62). What are the multivibrators constructed using 555 Timer? Astable Multivibrator Monostable Multivibrator Bistable Multivibrator a, b and c HintAll the types of Multivibrators63). How many comparators are present in Timer 555? Five Four Three Two HintUpper and Lower comparators64). Which is the most simple circuit constructed using Timer 555? Bistable multivibrator Monostable multivibrator Astable multivibrator Tetra stable multivibrator HintBistable circuit without any required RC external network65). In which applications 555 timer can be used? Multivibrators Pulse width modulation Oscillators a, b and c Hint555 is used to function as a timer commercially66). What are the components connected to timer 555 to function it as Astable multivibrator? Two Resistors Capacitor a and b Diode HintA capacitor and two resistors connected externally67). How Pulse position modulation is achieved using 555 Timer? Operating at Astable mode Operating at Monostable mode Operating as Astable and Monostable modes Operating at Bistable mode HintTwo Timers of 555 Integrated circuits68). Why 555 Integrated circuit used in the multivibrators? Easily available Complex in design Only Astable circuit is designed Only Bistable circuit can be designed HintEasy availability69). To achieve PPM the first 555 IC will be operated in __________ mode. Astable Bistable Monostable Astable and Monostable Hint555 IC functioning in Astable mode70). To which pin modulation signal is applied in 555 Timer? Pin 5 Pin 4 Pin 3 Pin 2 HintPin 5 of the 555 IC71). From which of the pins the output of PPM can be collected? Pin 5 Pin 4 Pin 3 Pin 2 HintPPM wave can be collected from Pin 372). How the time constant of a capacitor to charge and discharge related in Astable 555 circuit? Time constant of charging > Discharging Time constant of charging < Discharging Time constant of charging = Discharging Time constant of charging & Discharging are same HintThe time constant of the capacitor to charge is greater73). High output stays __________ in comparison with the Low Output in Astable circuit. Shorter Longer Equivalent Symmetric HintHigher output stays longer in duration74). What is the characteristic of the output obtained by Astable circuit? Symmetric Asymmetric Similar Proportionate HintAstable circuit is Asymmetric75). What do you define as TON / T? Time constant Charging time Duty cycle Discharging time HintDuty cycle for the High outputMultivibrators MCQs with Answers76). T in the duty cycle stands for _______. One cycle Time interval Multiple cycles Time interval Charging Time interval Discharging Time interval HintT = TON + TOFF77). How can you define Duty cycle? Relation amid High and Low output Relation between Time constants Relation between Resistors Relation between capacitors HintRelationship between the High and the Low outcomes78). How the charging time TC calculated in 555 Astable circuit? 0.6938*C (R1+ R2) 0.693*C (R1+ R2) 0.7938*C(R1+ R2) 0.693*C(R1) HintDependent on Resistors and Capacitors79). What is the discharge timing of an Astable circuit of 555? 0.6938*C (R1+ R2) 0.693*C (R2) 0.7938*C (R1+ R2) 0.693*C(R1) HintDischarge timing can be calculated based on the resistor R280). What is the component connected to 555 circuit to obtain Frequency Modulation? High pass filter Low pass filter Band pass filter Band reject filter HintModulation signal is applied it passes through an HPF81). Which device connected Astable circuit to achieve FM? FET MOSFET UJT Diode HintTo the Resistor (R2) diode connected in a parallel manner82). Astable circuit to achieve FM’s Modulation signal voltage and time period are ______. Directly proportional Inversely proportional Same Asymmetric HintModulation signal has a higher voltage the time interval of the obtained signal at output is higher83). Can an Astable multivibrator able to generate pulse of various widths? Yes No Impossible Can’t say HintReplacing a resistor with a potentiometer84). What sets the voltage to high in Monostable circuit? Rising edge Falling edge Positive edge Leading edge HintFalling edge at Pin 285). What are the components necessary to make 555 as Monostable circuit? Resistor Capacitor Diode a & b HintTwo components86). In Linear ramp generation circuit what is used as constant source of current? Current mirror Diode Transistor (PNP) All as mentioned earlier HintLinear ramp generator a constant source of current must be added87). What circuit is used as a missing pulse detector? Astable Bistable Monostable Astable and Monostable HintMonostable circuit with certain addition of components88). What components can make Monostable circuit as Missing pulse detector? Resistor Capacitor Transistor (PNP) b & c HintA transistor (PNP) connected over a capacitor externally89). What type of wave is generated by Free-running Multivibrators? Triangular Square Saw tooth Sine HintA free-running multivibrator90). Which circuit is referred to as Pulse Generator Circuit? Amplifiers Rectifiers Multivibrator Frequency divider HintMultivibrators are known for generating pulses91). Which multivibrators are used as Memory elements? Astable Bistable Monostable Astable and Monostable HintFlip-flops92). Discharge time of a capacitor in a Monostable circuit is termed as _________ time. Saturation Static Dynamic Recovery HintRecovery time93). Which element in Monostable circuit of CMOS prevent rising of input signal? Diode Transistor Inductor Capacitor HintCapacitors are used in the Monostable circuit made of CMOS94). The output finite resistance in the Astable circuit of CMOS can be ______. Finite Infinite Negotiable Certain Ohms HintAstable circuit of CMOS can be neglected95). Which type of Multivibrator generates Clock pulse? Astable Bistable Monostable Astable and Monostable HintMonostable multivibrators96). Bistable multivibrator is a _______. Oscillator Schmitt trigger Comparator Amplifier HintFlip-flop97). What is the outcome of the Schmitt trigger? Sine wave Triangular wave Saw-tooth wave Square wave HintSchmitt triggers98). What are the components required in building Op-amp based Astable circuit? Op-amp Resistors & Capacitor Diode a, b and c HintOp-amp with resistor-capacitor and diode99). A Monostable circuit with resistance (R) 100 Kilo ohms with a Time delay (T) of 1000 milliseconds. Find the Capacitor value? 1.23 micro farads 7.6 micro farads 9.09 micro farads 10.01 micro farads HintDelay in Monostable multivibrator can be calculated by 1.1 RC.100). A Monostable circuit with resistance (R) as 100 kilo ohms and capacitor (C) as 10 micro farads calculate the Time delay? 100 milli seconds 1000 milli seconds 1100 milli seconds 1200 milli seconds HintDelay in Monostable multivibrator can be calculated by 1.1 RC. Time is Up! Time's up
