Mini mock test Iti Electrician/Wireman Rrb ALP

1➤ Determine the full-pitch of a 3-phase, 36 slots, 36 coils, 6 poles motor

691218

2➤ The per-unit impedance is directly proportional to

Square root of base KVABase KVASquare of base voltageSquare root of base voltage

3➤ Creeping is the phenomenon which occurs in:-

WattmeterAmmeterEnergy meterVoltmeter

4➤ A three phase 4 wire system is commonly used for

Secondary transmissionSecondary distributionPrimary transmissionPrimary distribution

5➤ Which of the following is NOT a source of electricity?

HeatPressureLightSound

6➤ Resistor stores the energy in the form of

Electrical fieldMagnetic field Both 1 and 2 None of the above

7➤ Ohm's law can be applied to

Zener DiodeRectifierResistorTransformer

8➤ Instantaneous power in inductor is proportional to the .

Square of the rate of change of currentSquare of instantaneous currentTemperature of the inductorProduct of the instantaneous current and rate of change of current

9➤ Which one of the following law is based on the principle of conservation of electric charge?

Coulomb's LawOhm's LawKirchhoff's Voltage LawKirchhoff's Current Law

10➤ Change in resistance per ohm per degree centigrade is called

Temperature coefficient of resistanceMechanical equivalent of heatLaws of resistanceSpecific resistance

11➤ What will happen to the capacitor when the source is removed?

It will become zeroIt will start dischargingIt will remain in its charged stateIt will not remain in its charged state

12➤ Photo resistor is also known as

RTDVDRLEDLDR

13➤ Which capacitor will be physically smaller for the same ratings?

Paper capacitorCeramic capacitor Both will of same sizeNone of the above

14➤ Pressure pushes the electrons in a circuit is called

TemperatureVoltageFrequencyResistance

15➤ HP is equivalent to how many watts?

744745743746

16➤ Resistance of 250 V, 100 W lamp will be

2.5 ohm625 ohm25 ohm 0.4 ohm

17➤ What is the SI unit of resistance?

Ohm meterOhmAmpereCoulomb

18➤ The turns ratio of an isolation transformer is:

1:2 2:11:11:3

19➤ Resistance can be measured using:

OhmmeterVoltmeterWattmeterAmmeter

20➤ Four resistors with 4 Q are connected in parallel. The total resistance is:

16Ω1Ω4Ω 8Ω

21➤ Inter poles in DC machines are used to

Reduce the effect of coggingReduce the effect of crawlingReduce the effect of armature reactionNone of these

22➤ The relationship between back e.m.f and applied voltage in case of a d.c. motor is as:

Eb = V - laRa Eb = V + laRa Eb= VNone of these

23➤ Which motor is used for power factor improvement?

DC series motorOver excited synchronous motorUnder exited synchronous motorInduction motor

24➤ Fill in the blanks The_______ Circuit, means the switch is______ and current is flowing in the circuit.

Closed, ON Closed, OFF Open, ONNone is correct

25➤ Which one of the following motors can reverse its direction of rotation by simply reversing the supply connections?

Shaded pole motorSplit phase motorCapacitor start capacitor run motorNone of the above

26➤ The detailed form of V.I.R. wire is

Valuable Indian RubberVulcanised inducting rubberVulcanised Indian RubberVarnished insulating rubber

27➤ The heating element of an electric iron is made up of:

IronCopperAluminiumNichrome

28➤ A hysteresis motor

Needs dc excitationIs not a self-starting motor Is a constant speed motorCannot be run in reverse speed

29➤ Induction motor rotor always rotate at a speed than synchronous speed

infinitelessgreatersame

30➤ The frequency of the DC system in India is

110Hz60Hz0Hz50Hz

31➤ What happens when an alternator is said to be over excited?

Leading power factorUnity power factor Lagging power factorNegative power factor

32➤ Which of the following motor is used in household refrigerator?

3-Phase induction motorSynchronous motor 1-phase induction motorDC shunt motor

33➤ What is the rotor current frequency when the slip is 3% for a 4 pole 60 Hz 3 phase squirrel cage induction motor?

50 Hz3 Hz1.5 Hz1.8 Hz

34➤ The primary winding of a 230/6 V, 50 Hz transformer is energized from 110 V, 50 Hz supply. The secondary output voltage will be

4.12 V6.0 V 3.0 V 2.86 V

35➤ When speed of motor is zero, then slip will be

Zero50%100%1%

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