ELECTRICIAN- AC Circuits MCQ

Prepare for your examinations with a set of multiple choice questions (MCQs) related to AC Circuits for Electrician Trade. The questions are likely designed to test a user’s knowledge or understanding of electrical concepts and may be useful for exam preparation or self-assessment. The website may be a helpful resource for individuals studying to become electricians or seeking to improve their understanding of electrical principles.

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AC CIRCUITS

What is the unit of susceptance?MhoOhmHenryFarad

How the resonance frequency (fr) can be increased in A.C series circuit?Increasing the inductance valueReducing the capacitance valueIncreasing the capacitance valueIncreasing the resistance value

What is the main cause for below 0.5 lagging power factor in 3 phase system?Due to fluctuation of voltageTrue power due to resistive loadReactive power due to more inductive loadReactive power due to more capacitive load

What is the current in neutral conductor in 3 phase unbalanced load in star connected system?No current will flowThe algebraic sum of current in 3 phasesThe algebraic sum of current in 2 phases onlyLesser than the lowest current in any one of the phases

What will be the readings of two watt meters (W1& W2) in 3 phase power measurement, if the power factor is zero?W1 & W2 both are positive readingW1 is Positive and W2 is negative readingW1 is equal to W2 but with opposite signsZero W1 is Positive reading, and W2 is negative reading

What is the maximum value of voltage for 240 volt RMS?240V415V339.5V376.8V

What is the formula for Reactive Power (Pr) in an AC circuit?Pr = VIPr = √2 VIPr = VI cos θPr = VI sin θ

What is the phase displacement in a single phase AC circuit?90°120°180°270°

What is the power factor in a 3 phase power measurement of two wattmeter showing equal readings?010.50.8

Calculate the power factor of coil having resistance of 24Ω, draws the current of 5A, at 240V/ 50HZ AC supply.0.80.60.50.3

Calculate the power factor of R.L.C circuit having resistance (R) = 15W, resultant reactance (X) = 20W connected across 240V /50Hz AC supply?0.50.60.70.8

Calculate the value admittance (Y) of the RLC parallel circuit connected across 240 volts/50Hz AC supply and 8 Amp. Current is passed through it ?3.33 Mhoi0.33 Mho0.033 Mho0.0033

How the low power factor (P.F) can be improved in AC circuits?By connecting resistors in seriesBy connecting capacitors in seriesBy connecting inductors in seriesBy connecting capacitors in parallel

What is the relation between the line current (IL) and phase current (IP) in delta connected system?IL = IPIL = 3 IPIL = √3 IPIL = IP / √3

What is the purpose of phase sequence meter?To control the speed of 3 phase motorTo protect motor against short circuit faultTo indicate the incorrect phase sequence of 3 phaseTo ensure the correct phase sequence of 3 phase system

Calculate the apparent power of a star connected 3 phase load, if it is connected across 3 phase 415 volt/50Hz supply at 0.8 p.f and the phase current is 10 Amps.12. 45 KVA57.50 KVA3.320 KVA7.188 KVA

What is the P.F if one of the wattmeters reading is zero and the other reads total power in 2 wattmeter method of 3 phase power measurement?0.501Below 0.5

What is the formula for form factor (Kf)?Kf= Average value / RMS valueKf= RMS value / Average valueKf= Maximum value / Average valueKf= RMS value / Maximum value

Which electrical term is defined as the total opposition to current in AC parallel circuit?ResistanceImpedanceAdmittanceSusceptance

Which AC circuit contains the phase relation between voltage (V) and current (I)?Pure resistive circuitResistance and inductance circuitResistance and capacitance circuitResistance, inductance and capacitance circuit

In a 3 phase system, if the active power is 4kw and the apparent power is 5 KVA, calculate the reactive power?1 KVAR2 KVAR3 KVAR4 KVAR

In which condition resonance will occur in an RLC series circuit?Inductive reactance (XL) is zeroInductive reactance (XL) is equal to capacitive reactance (XC)Inductive reactance (XL) is greater than capacitive reactance (XC)Inductive reactance (XL) is less than capacitive reactance (XC)

How will you obtain positive reading in the wattmeter reads negative reading during 3- phase two wattmeter method?By interchanging the connections of input terminalsBy disconnecting the connection of current coil in meterBy reversing the connection of pressure coil in meterBy reversing the connection of pressure coil in meter

What is the form factor (Kf) for sinusoidal AC?11.112.224.44

What is the reciprocal of inductance in AC parallel circuit?ReactanceAdmittanceConductanceSusceptance

Calculate the total power by two wattmeter(W1 & W2) method, if one of the wattmeter (W2)reading is taken after reversing.W1 x 2W1 onlyW1 - W2W1 + W2

Which 3 phase system, the artificial neutral is required to measure the phase voltage?3 wire star connected system4 wire star connected system3 wire delta connected system4 wire delta connected system

What is the line voltage in 3 phase system if the phase voltage is 240V?380 Volt400 Volt415 Volt440 Volt

What is the power factor if one of the wattmeter gives negative reading in two wattmeter method of 3 phase power measurement?00.51Less than 0.5

What is the phase displacement between phases in a 3-phase circuit?90°120°180°360°

Which condition is called as resonance RLC circuit?XL > XCXC > XLXL = XCR < XL