McQ ITI Technician/Instructor/JE Wireman

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 starter

2➤ 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 Vac

3➤ Which material is used for making heat sink?

ZincCopperAluminiumIron

4➤ What is the PIV of the diode if the AC input voltage is 24V?

36 V34 V 32 V33 V

5➤ How the N type semi conductor is formed?

Silicon with arsenicSilicon with iridiumSilicon with antimonyGermanium with aluminium

6➤ How many electrons in a silicon atom? A : B : C : D :

327 1429

7➤ 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 method

9➤ 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 earthing

10➤ Why earth resistance value required to keep very low?

For low voltage dropFor low power consumptionFor easy measurementFor quick current flow

11➤ 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 load

15➤ 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 system

16➤ What is the name of star point in star connection system?

Phase tapping wireCross pointTapping pointNeutral point

17➤ What is impedance in AC, RL series circuit if resistance is 3 ohm and inductive reactance 4 ohm?

12 ohm5 ohm3 ohm 7 ohm

18➤ 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 motor

19➤ Which device is used in control of a star delta starter to stop the motor?

Normally closed push buttonStar contactorDelta contactor OLR

20➤ Which part of squirrel cage rotor is short circuited?

BearingsShaftEnd ringsEnd cover hysteresis

Your score is