Electrician 1st sem – NSQF – Module 6 – AC circuits mock Test July 2, 2025June 19, 2025 by admin TRANSLATE THIS QUIZ IN YOUR LANGUAGE इस प्रश्नोत्तरी का अपनी भाषा में अनुवाद करें <<1234567891011121314151617181920212223242526272829303132333435363738394041424344>> 0% Question 1 of 44 1. What is the current in neutral conductor in 3 phase unbalanced load in star connected system? The algebraic sum of current in 2 phases only No current will flow The algebraic sum of current in 3 phases Lesser than the lowest current in any one of the phasesRate this question: Loading... Question 1 of 44Question 2 of 44 2. What is the main cause for below 0.5 lagging power factor in 3 phase system? True power due to resistive load Due to fluctuation of voltage Reactive power due to more capacitive load Reactive power due to more inductive loadRate this question: Loading... Question 2 of 44Question 3 of 44 3. Which formula is used to calculate the impedance (z) of a RLC series circuit?Z = R² + (XL ∼ XC)² Z = R + (XC - XL)Z = √R² + (XL ∼ XC)²Z = √R + (XL ∼ XC)Rate this question: Loading... Question 3 of 44Question 4 of 44 4. What is the condition for resonance in RLC series circuit? (Inductive reactance = 'XL', Capacitive reactance = 'XC')XL = XCXL >√2 XCXL < XCXL > XCRate this question: Loading... Question 4 of 44Question 5 of 44 5. How will you obtain positive reading in the wattmeter reads negative reading during 3-phase two wattmeter method? By disconnecting the connection of current coil in meter By reversing the connection of pressure coil in meter By interchanging the connections of input terminals By reversing the pressure coil and current coil connection in meterRate this question: Loading... Question 5 of 44Question 6 of 44 6. What is the power factor if one of the wattmeter gives negative reading in two wattmeter method of 3 phase power measurement? Unity Less than 0.5 0.5 0Rate this question: Loading... Question 6 of 44Question 7 of 44 7. What is the purpose of phase sequence meter? To ensure the correct phase sequence of 3 phase system To control the speed of 3 phase motor To indicate the incorrect phase sequence of 3 phase To protect motor against short circuit faultRate this question: Loading... Question 7 of 44Question 8 of 44 8. Which condition is called as resonance RLC circuit?R < XLXL = XCXL > XCXC > XLRate this question: Loading... Question 8 of 44Question 9 of 44 9. What is the line voltage in 3 phase system if the phase voltage is 240V? 440 Volt 380 Volt 400 Volt 415 VoltRate this question: Loading... Question 9 of 44Question 10 of 44 10. Calculate the power factor of coil having resistance of 24Ω, draws the current of 5A, at 240V/ 50Hz AC supply. 0.3 0.6 0.5 0.8Rate this question: Loading... Question 10 of 44Question 11 of 44 11. What relationship is illustrated in between the current and voltage? Current leads ahead of the voltage Current and voltage are "in phase" Current and voltage are in out of phase Current lags behind the voltageRate this question: Loading... Question 11 of 44Question 12 of 44 12. Which electrical term is defined as the total opposition to current in AC parallel circuit? Susceptance Resistance Admittance ImpedanceRate this question: Loading... Question 12 of 44Question 13 of 44 13. Which quantity is rotating at a constant angular velocity? Scalar quantity Phasor quantity Vector quantity Algebraic quantityRate this question: Loading... Question 13 of 44Question 14 of 44 14. In which condition resonance will occur in R-L-C series circuit?Inductive reactance (XL) is less than capacitive reactance (XC)Inductive reactance (XL) is zeroInductive reactance (XL) is equal to capacitive reactance (XC)Inductive reactance (XL) is greater than capacitive reactance (XC)Rate this question: Loading... Question 14 of 44Question 15 of 44 15. Which AC circuit contains the phase relation between voltage (V) and current (I)? Resistance, inductance and capacitance circuit Pure resistive circuit Resistance and inductance circuit Resistance and capacitance circuitRate this question: Loading... Question 15 of 44Question 16 of 44 16. What is the formula for Reactive Power (Pr ) in an AC circuit?(Pr )= VI(Pr ) = VI cos θ(Pr ) = √2 VI(Pr )= VI sin θRate this question: Loading... Question 16 of 44Question 17 of 44 17. What is the formula to find 3 phase Reactive power (PR) if the line voltage is 'VL' and line current is 'IL'?Pr = √3VL IL SinθPr = VL ILPr = 3VL IL CosθPr = √3VL IL CosθRate this question: Loading... Question 17 of 44Question 18 of 44 18. What is the maximum value of voltage for 240 volt RMS? 415V 376.8V 240V 339.5VRate this question: Loading... Question 18 of 44Question 19 of 44 19. 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? 0.5 Unity Below 0.5 ZeroRate this question: Loading... Question 19 of 44Question 20 of 44 20. What is the relation between the line current (IL ) and phase current (IP ) in delta connected system?IL = 3 IPIL = IP /√3IL = IPIL = √3 IPRate this question: Loading... Question 20 of 44Question 21 of 44 21. Calculate the value admittance (Y) of the RLC parallel circuit connected across 240volts/50Hz AC supply and 8 Amp. Current is passed through it? 0.33 Mho 3.33 Mho 0.033 Mho 0.003 MhoRate this question: Loading... Question 21 of 44Question 22 of 44 22. In which 3 phase system, the artificial neutral is required to measure the phase voltage? 4 wire delta connected system 3 wire star connected system 3 wire delta connected system 4 wire star connected systemRate this question: Loading... Question 22 of 44Question 23 of 44 23. What is the formula to calculate the impedance (Z) of the R.L.C series circuit, if the inductive reactance (XL ) is less than capacitive rectance (XC)? Z Z Z Z Rate this question: Loading... Question 23 of 44Question 24 of 44 24. What is the resistance of the inductive coil takes 5A current across 240V, 50Hz supply at 0.8 power factor? 38.4Ω 26.6Ω 42.5Ω 48 ΩRate this question: Loading... Question 24 of 44Question 25 of 44 25. What is the phase displacement between phases in a 3 phase circuit? 180° 90° 360° 120°Rate this question: Loading... Question 25 of 44Question 26 of 44 26. Calculate the line current of the 3 phase 415V 50 HZ supply for the balanced load of 3000 watt at 0.8 power factor is connected in star. 3.4 A 4.5 A 5.2 A 8.5 ARate this question: Loading... Question 26 of 44Question 27 of 44 27. Calculate the impedance of the circuit R = 5Ω, XL = 36Ω and XC = 24 Ω. 69 Ω 13 Ω 65 Ω 12 ΩRate this question: Loading... Question 27 of 44Question 28 of 44 28. What is the power factor in a 3 phase power measurement of two wattmeters showing equal readings? 0.5 0 1 0.8Rate this question: Loading... Question 28 of 44Question 29 of 44 29. Calculate the apparent power of a star connected 3 phase load, if it is connected across 3 phase 415volt/50Hz supply at 0.8 p.f and the phase current is 10 Amps. 3.320 KVA 57.50 KVA 12.45 KVA 7.188 KVARate this question: Loading... Question 29 of 44Question 30 of 44 30. How the low power factor (P.F) can be improved in AC circuits? By connecting capacitors in series By connecting resistors in series By connecting capacitors in parallel By connecting inductors in seriesRate this question: Loading... Question 30 of 44Question 31 of 44 31. What is the form factor (Kf) for sinusoidal AC? 4.44 1.00 1.11 2.22Rate this question: Loading... Question 31 of 44Question 32 of 44 32. What is the reciprocal of inductance in AC parallel circuit? Reactance Susceptance Admittance ConductanceRate this question: Loading... Question 32 of 44Question 33 of 44 33. What is the formula to calculate the three phase active power (P) if the line voltage (VL ) and line current is IL and phase angle is 'θ'?P = √ 3 VL IL CosθP = 3 VL IL CosθP = √ 3 VL IL SinθP = 3 VL IL SinθRate this question: Loading... Question 33 of 44Question 34 of 44 34. What will be the readings of two watt meters (W1 & W2) in 3 phase power measurement, if the power factor is zero?Zero W1is Positive reading, and W2 is negative readingW1 & W2 both are positive readingW1 & is Positive and W 2 is negative readingW1 is equal to W2 but with opposite signsRate this question: Loading... Question 34 of 44Question 35 of 44 35. Calculate the total power by two wattmeter (W1 & W2) method, if one of the wattmeter (W2) reading is taken after reversing.W1 x 2W1 + W2W1 onlyW1 - W2Rate this question: Loading... Question 35 of 44Question 36 of 44 36. What is the phase displacement in a single phase AC circuit? 90° 270° 180° 120°Rate this question: Loading... Question 36 of 44Question 37 of 44 37. What is the relation between the line voltage (V L ) and phase voltage (Vp) in star connected system?VL = 3VpVL =V p /3VL = √3VpVL = Vp /√3Rate this question: Loading... Question 37 of 44Question 38 of 44 38. Which formula is used to calculate Form factor (Kf)?Kf = Maximum value/Average valueKf= Maximum value/Effective valueKf = Average value/Effective valueKf= Effective value/Average valueRate this question: Loading... Question 38 of 44Question 39 of 44 39. What is the formula to calculate the line current (IL) of this single phase R - C parallel circuit? IL= IR² + IC²IL= √IR² + IC² IL = IR - ICIL= IR + ICRate this question: Loading... Question 39 of 44Question 40 of 44 40. Calculate the power factor of R.L.C circuit having resistance (R) = 15Ω, resultant reactance (X) = 20Ω connected across 240V /50Hz AC supply? 0.7 0.8 0.6 0.5Rate this question: Loading... Question 40 of 44Question 41 of 44 41. What is the unit of susceptance? Henry Ohm Mho FaradRate this question: Loading... Question 41 of 44Question 42 of 44 42. In a 3 phase system, if the active power is 4 kw and the apparent power is 5 KVA, calculate the reactive power? 3 KVAR 2 KVAR 4 KVAR 1 KVARRate this question: Loading... Question 42 of 44Question 43 of 44 43. Calculate the apparent power in KVA of 3 phase 415V, 50 Hz, star system, if the line current (I L ) is 16A at 0.8 power factor. 15.2 KVA 9.2 KVA 5.3 KVA 11.5 KVARate this question: Loading... Question 43 of 44Question 44 of 44 44. How the resonance frequency (fr) can be increased in A.C series circuit? Increasing the capacitance value Increasing the value of resistance Increasing the inductance value Reducing the capacitance valueRate this question: Loading... Question 44 of 44 Loading...
