HomeElectrician ITI/ Wireman ITIMcQ ITI Technician/Instructor/JE Wireman McQ ITI Technician/Instructor/JE Wireman Education May 19, 2023 0 1➤ Which type of starter is used with reduced voltage tappings for 3 phase induction motor? Rotor resistance starterAuto transformer starterStar delta starterD.O.L starter2➤ What is the relation between input AC voltage (VAC) and output DC voltage (VDC) in full wave rectifier? : Vdc = 0.9 VacVdc = 0.637 Vac Vdc = 0.45 VacVdc = 0.707 Vac3➤ Which material is used for making heat sink? ZincCopperAluminiumIron4➤ What is the PIV of the diode if the AC input voltage is 24V? 36 V34 V 32 V33 V5➤ How the N type semi conductor is formed?Silicon with arsenicSilicon with iridiumSilicon with antimonyGermanium with aluminium6➤ How many electrons in a silicon atom? A : B : C : D : 327 14297➤ How many primary winding required in ELCB? Four primary windingsThree primary windingsOne primary windingTwo primary windings 8➤ What principle earth tester works? Current dividing methodFall of potential methodFall of resistance methodPotential dividing method9➤ Which method is used to reduce earth resistance? Decreasing the length of the electrodeIncreasing the depth of earth pitConnecting number of earth electrode in parallelReducing the pit depth for earthing10➤ Why earth resistance value required to keep very low? For low voltage dropFor low power consumptionFor easy measurementFor quick current flow11➤ What is the minimum length of the earth electrode pipe? 2.5 metre2 metre2.25 metre1.5 metre 12➤ What will happen to the value of earth resistance, if length of the earth pipe is increased? InfinityDecreasesIncreasesRemain same 13➤ Which type of starter is used with reduced voltage tappings for 3 phase induction motor? A : B : C : D : Rotor resistance starterAuto transformer starterStar delta starter D.O.L starter 14➤ What is the purpose of system earthing? A : B : C : D : To reduce the lossesTo maintain ground at zero potential To reduce the load currentTo protect the equipment from over load15➤ Where the artificial neutral is required for measuring phase voltage in 3 phase circuit? 4 wire delta connected system3 wire delta connected system4 wire star connected system 3 wire star connected system16➤ What is the name of star point in star connection system? Phase tapping wireCross pointTapping pointNeutral point17➤ What is impedance in AC, RL series circuit if resistance is 3 ohm and inductive reactance 4 ohm? 12 ohm5 ohm3 ohm 7 ohm18➤ Which induction motor, the external resistance is added to rotor circuit? Single phase induction motorSlip ring induction motor Double squirrel cage induction motorSquirrel cage induction motor19➤ Which device is used in control of a star delta starter to stop the motor? Normally closed push buttonStar contactorDelta contactor OLR20➤ Which part of squirrel cage rotor is short circuited? BearingsShaftEnd ringsEnd cover hysteresis SubmitYour score is Tags Electrician ITI/ Wireman ITI Newer Older