Alternating Current and Voltage Question & AnswersSeptember 13, 2021 By Wat Electrical Leave a Comment This article lists 100 Alternating Current and Voltage MCQs for engineering students. All the Alternating Current and Voltage Questions & Answers given below includes solution and link wherever possible to the relevant topic.In the 1880s the DC was discovered by Thomas Edison and the AC was discovered by Nikola Tesla. The electricity we use in our homes and offices is generated in power stations. The electricity produced in power stations is delivered by transmission lines over a long distance, and the amount of power generated is given by a product of current and voltage. In India, the electricity standards are 230 volts and 50 hertz. 1). The power factor of an AC voltage lies between ______________ 0 and 1 1 and 2 2 and 3 3 and 4 HintThe power factor of an AC voltage lies between zero and one 2). The alternating current voltage have _______________ Phase Neutral Both a and b None of the above HintThe alternating current voltage has both phase and neutral3). Which one of the following requires for transmission? AC voltage DC voltage Both a and b None of the above HintAn AC voltage is required for transmission4). Which one of the following doesn’t have amplitude? AC voltage DC voltage Both a and b None of the above HintThe DC voltage doesn’t have an amplitude5). The passive parameter in an AC voltage is _________ Impedance Resistance Both a and b None of the above HintThe passive parameter in an AC voltage is impedance6). The ratio of real power divided by apparent power is known as _____________ Apparent power Power factor Reactive factor None of the above HintThe ratio of real power divided by apparent power is known as the power factor7). The expression for capacitive reactance is given by _____________ 1/ꙍC ꙍL WC None of the above HintThe expression for capacitive reactance is given by 1/ꙍC8). The ratio f reactive power divided by apparent power is known as __________ Apparent power Power factor Reactive factor None of the above HintThe ratio f reactive power divided by apparent power is known as reactive power9). Which one of the following voltages is obtained from a generator? AC voltage DC voltage Both a and b None of the above HintAn AC voltage is obtained from a generator10). Which one of the following voltages is unidirectional? AC voltage DC voltage Both a and b None of the above HintThe direction of an AC voltage is unidirectional11). Which one of the following currents is discovered by Thomas Edison? AC DC Both a and b None of the above HintThe direct current is discovered by Thomas Edison12). Which one of the following currents is discovered by Nikola Tesla? AC DC Both a and b None of the above HintAn alternating current is discovered by Nikola Tesla13). The expression for inductive reactance is given by _____________ 1/ꙍC ꙍL WC None of the above HintThe expression for inductive reactance is given by ꙍL14). The expression for power loss is equal to ___________ IR I^2 * R 2R 1/R HintThe expression for power loss is equal to I^2 * R15). In India the electricity standards are _____________ 10 volts and 50 hertz 30 volts and 50 hertz 20 volts and 50 hertz 230 volts and 50 hertz HintIn India, the electricity standards are 230 volts and 50 hertz16). In US the electricity standards are _____________ 10 volts and 50 hertz 30 volts and 50 hertz 120 volts and 60 hertz 230 volts and 50 hertz HintIn the US the electricity standards are 120 volts and 60 hertz17). How many cycles does AC produce per second? 10 cycles 20 cycles 30 cycles 50 cycles HintAn alternating current produces 50 cycles per second18). The period of a wave is related to ___________ quantity Rate Time Frequency None of the above HintThe period of a wave is related to time quantity 19). The frequency of a wave is related to ___________ quantity Rate Time Frequency None of the above HintThe frequency of a wave is related to rate quantity 20). Which one of the following is expressed in seconds per cycle? Rate Time Period None of the above HintThe period is expressed in seconds per cycle21). Which one of the following is expressed in cycles per second? Frequency Time Period None of the above HintThe frequency is expressed in cycles per second22). The expression for voltage amplitude is given by _____________ 1/ꙍC IꙍL WC None of the above HintThe expression for voltage amplitude is given by IꙍL23). The frequency is _________ if the period is longer Higher Lower Constant Moderate HintThe frequency is lower if the period is longer24). The period is _________ if the frequency is higher Higher Lower Constant Moderate HintThe period is lower if the frequency is higher25). What is the unit to measure bandwidth? Ohms Bits/sec Hz None of the above HintThe unit to measure bandwidth is bits/secAlternating Current and Voltage Important MCQs26). The induced EMF is categorized into ________________ One Two Three Four HintThe induced EMF is categorized into two types they are dynamically induced and statically induced EMF27). The statically induced EMF is categorized into _______________ One Two Three Four HintThe statically induced EMF is categorized into two types they are self-induced and mutually induced EMF28). In _______________ phase the power supplies through one conductor Single Two Three None of the above HintIn single-phase, the power supplies through one conductor29). The number of wires required for completing the single-phase circuit is ____________ One Two Three Four HintThe number of wires required for completing the single-phase circuit is two30). The single-phase alternating current circuit carries ____________ 100 volts 110 volts 200 volts 230 volts HintThe single-phase alternating current circuit carries 230 volts31). In which one of the following phases the efficiency is high? Single Double Three None of the above HintIn three-phase, the efficiency is high compare to single phase32). In _______________ phase the power supplies through three conductors Single Two Three None of the above HintIn three-phase the power supplies through three conductors33). Which one of the following phases is more economical? Single Double Three None of the above HintIn three-phase is more economical compare to single phase 34). The loss is maximum in __________ phase Single Double Three None of the above HintThe loss is maximum in a single phase35). The phase impedances in balanced load are equal in __________ Phase Magnitude Both a and b None of the above HintThe phase impedances in balanced load are equal in both phase and magnitude36). The transmission efficiency is high in __________ phase system Single Double Three None of the above HintThe transmission efficiency is high in a three-phase system 37). The cross-sectional area of conductors are large in _________ phase system Single Double Three None of the above HintThe cross-sectional area of conductors are large in a single-phase system Read more about Electrical Conductors38). In which one of the following voltage the polarity is fixed? AC voltage DC voltage Both a and b None of the above HintIn DC voltage the polarity is fixed whereas in AC voltage the polarity is not fixed39). The number of wires required for completing the three-phase circuit is ____________ One Two Three Four HintThe number of wires required for completing the three-phase circuit is four40). Which one of the following is easier to measure? AC voltage DC voltage Both a and b None of the above HintThe DC voltage is easier to measure41). Which one of the following is easier to amplify? AC voltage DC voltage Both a and b None of the above HintAn AC voltage is easier to amplify42). The RMS value of the sine waveform is __________ 1.414 0.7071 1.11 None of the above HintThe RMS value of the sine waveform is 0.707143). The crest factor value of sine waveform is ____________ 1.414 0.7071 1.11 None of the above HintThe crest factor value of sine waveform is 1.41444). The three-phase alternating current circuit carries ____________ 100 volts 110 volts 200 volts 415 volts HintThe three-phase alternating current circuit carries 415 volts45). The form factor value of sine waveform is ____________ 1.414 0.7071 1.11 None of the above HintThe form factor value of sine waveform is 1.1146). The ratio of RMS value divided by average value is known as ____________ factor Peak Form Crest None of the above HintThe ratio of RMS value divided by average value is known as form factor47). The ripple factor is defined as a ratio of _______________ Peak voltage/DC voltage Peak voltage/AC voltage (RMS voltage/DC voltage)*100 None of the above HintThe ripple factor is defined as a ratio of (RMS voltage/DC voltage)*10048). Which one of the following phase networks is complicated? Single Double Three None of the above HintIn three-phase network is complicated compare to single phase 49). The RMS value of the triangular waveform is __________ 1.414 0.7071 0.577 None of the above HintThe RMS value of the triangular waveform is 0.57750). The crest factor value of the triangular waveform is ____________ 1.414 0.7071 1.732 None of the above HintThe crest factor value of the triangular waveform is 1.732Alternating Current and Voltage MCQs for Quiz51). The form factor value of the triangular waveform is ____________ 1.414 0.7071 1.154 None of the above HintThe form factor value of the triangular waveform is 1.15452). The mean value of the sine wave is ____________ 0.637 0.318 0.5 1 HintThe mean value of the sine wave is 0.63753). The peak to average power ratio of sine wave is _______________ 3.01 dB 6.02 dB 4.77 dB None of the above HintThe peak to average power ratio of the sine wave is 3.01 dB54). The ratio of peak value divided by RMS value is known as ____________ factor Peak Form Crest None of the above HintThe ratio of peak value divided by RMS value is known as crest factor55). The power factor of the series resonance circuit is ________________ Zero Infinity One Unity HintThe power factor of the series resonance circuit is unity56). The RMS value of the square waveform is __________ 1.414 0.7071 0.577 1 HintThe RMS value of the square waveform is one57). The crest factor value of the square waveform is ____________ 1.414 0.7071 1 None of the above HintThe crest factor value of the square waveform is one58). The form factor value of the square waveform is ____________ 1.414 0.7071 1.154 One HintThe form factor value of the square waveform is one59). The mean value of the half-wave rectified sine is ____________ 0.637 0.318 0.5 1 HintThe mean value of the half-wave rectified sine is 0.31860). Which one of the following circuits magnifies voltage? Series resonance Parallel resonance Both a and b None of the above HintThe series resonance circuit magnifies voltage61). Which one of the following circuits is also known as the acceptor circuit? Series resonance Parallel resonance Both a and b None of the above HintThe series resonance circuit is also known as the acceptor circuit62). The power factor at resonance is unity in ______________ circuit Series RLC Parallel RLC Both a and b None of the above HintThe power factor at resonance is unity in both series and parallel circuit63). The ratio of inductor voltage or capacitor voltage by supply voltage is known as ___________ factor Quality Crest Peak None of the above HintThe ratio of inductor voltage or capacitor voltage by supply voltage is known as the quality factor64). The RMS value of saw-tooth waveform is __________ 1.414 0.7071 0.577 1 HintThe RMS value of the saw-tooth waveform is 0.57765). The crest factor value of saw-tooth waveform is ____________ 1.732 0.7071 1 None of the above HintThe crest factor value of the saw-tooth waveform is 1.73266). The form factor value of saw-tooth waveform is ____________ 1.414 0.7071 1.154 one HintThe form factor value of the saw-tooth waveform is 1.15467). The mean value of full-wave rectified sine is ____________ 0.637 0.318 0.5 1 HintThe mean value of full-wave rectified sine is 0.63768). The peak to average power ratio of full-wave rectified sine is ____________ 3.01 dB 6.02 dB 4.77 dB None of the above HintThe peak to average power ratio of full-wave rectified sine is 3.01 dB69). Which one of the following circuits magnifies current? Series resonance Parallel resonance Both a and b None of the above HintThe parallel resonance circuit magnifies current70). Which one of the following circuits is also known as the rejector circuit? Series resonance Parallel resonance Both a and b None of the above HintThe parallel resonance circuit is also known as the rejector circuit71). The ratio of bandwidth divided by resonant frequency is known as _____________ Quality factor Crest factor Selectivity None of the above HintThe ratio of bandwidth divided by resonant frequency is known as selectivity72). What is the unit of self-inductance? Ohm Henry Ampere None of the above HintThe unit of self-inductance is henry73). How many types of inductance are there? One Two Three Four HintThe inductances are of two types they are mutual and self-inductance74). The mean value of triangular wave is ____________ 0.637 0.318 0.5 1 HintThe mean value of triangular wave is 0.575). The peak to average power ratio of half-wave rectified sine is ____________ 3.01 dB 6.02 dB 4.77 dB None of the above HintThe peak to average power ratio of half-wave rectified sine is 6.02 dBAlternating Current and Voltage MCQs for Students Read more about Rectifier76). Which one of the following is a correct expression for resonant angular frequency? 1/√LC 1/LC 1/√RC None of the above HintThe resonant angular frequency is equal to 1/√LC77). Which one of the following is a capacitive reactance equation? 1/ꙍC 1/LC 1/RC None of the above HintThe expression for capacitive reactance is 1/ꙍC78). Which one of the following is an inductive reactance equation? 1/ꙍC 1/ꙍL 1/RC None of the above HintThe expression for inductive reactance is 1/ꙍL79). The root mean square of the current is known as ______________ RMS current RMS voltage Resonant frequency None of the above HintThe root mean square of the current is known as RMS current80). How many ways are there to measure the alternating current and voltage? One Two Three Four HintThere are three ways are there to measure the alternating current and voltage they are peak value, average or mean value, and RMS value81). Which one of the following is a current expression for angular velocity? ꙍ=2πf ꙍ=2f ꙍ=8πf None of the above HintThe current expression for angular velocity is ꙍ=2πf82). Which one of the following is also known as the amplitude factor? Resonance factor Crest factor Form factor None of the above HintThe crest factor is also known as the amplitude factor83). The peak to average power ratio of the triangular wave is ____________ 3.01 dB 6.02 dB 4.77 dB None of the above HintThe peak to average power ratio of the triangular wave is 4.77dB84). The root mean square of the voltage is known as ______________ RMS current RMS voltage Resonant frequency None of the above HintThe root mean square of the current is known as the RMS voltage85). What are the advantages of an alternating current? Cheaper than DC Can be stepped down or stepped up by transformer Can be converted into DC by rectifier All of the above HintThe advantages of an alternating current are cheaper than DC, can be stepped down or stepped up by transformer, and can be converted into DC by rectifier86). The magnetic field is stationary in ____________ motor AC DC Both a and b None of the above HintThe magnetic field is stationary in direct current motor87). The armature is stationary in ______________ motor AC DC Both a and b None of the above HintThe armature is stationary in alternating current motor88). Which one of the following generators doesn’t have a commutator? AC generators DC generators Both a and b None of the above HintThe AC generators don’t have a commutator89). Which one of the following motors doesn’t use brushes? AC motors DC motors Both a and b None of the above HintThe alternating current motors don’t use brushes90). What are the advantages of an AC motor? High power factor Low-cost Reliable All of the above HintThe AC motors have a high power factor, has low cost, and are reliable91). The number of terminals in an AC motor is ____________ One Two Three Four HintThe number of terminals in an AC motor is three they are RYB92). The mean value of the square wave is ____________ 0.637 0.318 0.5 1 HintThe mean value of the square wave is one93). The peak to average power ratio of the square wave is ____________ 3.01 dB 6.02 dB 0 dB None of the above HintThe peak to average power ratio of the square wave is 0 dB94). Which one of the following cannot produce the chemical effects of current? AC DC Both a and b None of the above HintAn alternating current cannot produce the chemical effects of current95). The DC can be converted into an AC by using _____________ Rectifiers Inverters Both a and b None of the above HintThe DC can be converted into an AC by using inverters96). The electrons in _____________ current moves only in one direction Direct Alternating Both a and b None of the above HintThe electrons in direct current move only in one direction97). The stability problems are less in _____________ servomotors Direct Alternating Both a and b None of the above HintThe stability problems are less in alternating current servomotors98). The efficiency is high in _____________ current servomotors Direct Alternating Both a and b None of the above HintThe efficiency is high in direct current servomotors Read more about AC Motors99). Which one of the following motors is self-starting? Direct Alternating Both a and b None of the above HintThe direct current motors is self-starting100). Which one of the following is a type of AC motor? Synchronous motor Induction motor AC commutator motor All of the above HintThe synchronous motor, induction motor, and AC commutator motor are the types of AC motors Time is Up! Time's up

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