Electrical MCQ test SSC je/Rrb je/pcmc je

1➤ Superheater is employed to: 1. remove moisture from the vapours 2. increase the temperature of vapours 3. heat the feed water Which of the given statements is incorrect?

31 and 22 and 31

2➤ The average load factor of thermal power plants in India is

20 – 30 %80 – 95 %35 – 45 %50 – 60 %

3➤ Which of the following is not a part of steam generating unit in thermal power plant

BoilerAlternator Air preheaterEconomizer

4➤ Which of the following is not an equipment of steam generating unit in thermal power plant

Regenerative type Air preheaterJet condenserFire tube boilersWater tube boilers

5➤ What would be the most important factor under consideration for the site selection of a thermal plant?

Cost and the type of landDistance from the populated area. Availability of fuelAvailability of water

6➤ What is the nominal pH value of water that is to be maintained in a steam raising thermal power station

14.37.08.50.0

7➤ As per ISI, in a building, the illumination level required for kitchen is

100 lux200 lux150 lux50 lux

8➤ All synchronous generators are invariably

1-phase star connected machines3-phase delta connected machines1-phase delta connected machines3-phase star connected machines

9➤ Gauss' law is applicable to determine the field due to-

A point chargeA finite line chargeA finite charged plane sheetNon-uniformly charged spherical shells

10➤ The total harmonic distortion (THD) is a measure of the-

Input vs output power factorTemperature sensitivityContribution of each harmonic to the total outputWaveform distortion

11➤ The minimum size of aluminium cable generally used for light and fan sub-circuits is 1/1.40 mm having current capacity of

10 A15 A2.25 A 20 A

12➤ In SI system, the base unit for the measurement of Luminous intensity is:

TeslaCandelaKelvinLumen

13➤ Which of the following alternatives will be cheaper?

A 100 HP A.C. three phase motorFour motors of 25 HP eachFive motors of 20 HP each Ten motors of 10 HP each

14➤ theorem is applicable to both linear and nonlinear circuits.

Thevenin'sSubstitutionSuperpositionNorton's

15➤ A boost regulator has input voltage of 4 V and the average output voltage of 20 V. The duty cycle is:

4/51/5 3/5 2/5

16➤ Instantaneous power in inductor is proportional to the

square of rate of change of currenttemperature of the inductor.product of instantaneous current and rate of change of currentsquare of instantaneous current

17➤ Which of the following is not a valid method of neutral grounding ?

Voltage transformer groundPulse transformer groundingReactance groundingSolid grounding

18➤ As per IE Rules, the terminal voltage must be within the_____ range, if the nominal voltage is 240 V.

215 V to 265 V228 V to 252 V220 V to 260 V 225 V to 255 V

19➤ Starting torque of DC series motor is

ZeroMediumHighVery low

20➤ If the input frequency of a bridge rectifier is 100 Hz, then the output frequency will be:

200 Hz400 Hz100 Hz 50 Hz

21➤ In an AC circuit, the current & voltage are out of phase by 90 degrees. The ammeter reads 2 A and voltmeter reads 1000 V. The power consumed is

1000 W180 Wzero2000 W

22➤ Identify the incorrect statement regarding power MOSFET.

These do not experience any minority charge carrier storageThese can be put in parallel to handle large currentsThe channel length is relatively large and channel width is relatively smallThese are so constructed as to avoid punch through

23➤ For a specific wiring in a building, the full load current is 10 A. what will be the maximum permissible leakage current?

0.005A0.003 A0.002A0.008A

24➤ The SI unit of permeability is:

Ampere turnsHenry/meterTeslaHenry-meter

25➤ When a V-V system is converted into a A-A system, the capacity of the system increases by

50%73.2%66.7%86.6%

26➤ A combinational circuit is the one in which output depends on the

Present input combination and the previous output Present input combination and the previous input combinationPresent and the previous outputInput combination at that time

27➤ Which of the following part is not located inside the cathode ray tube of the CRO?

Vertical deflection platesHorizontal deflection platesElectron gunTime base generator

28➤ Incremental fuel costs in Rs/MWh for a plant consisting of two generating units are given by dF/dP₁= 0.4P₁ + 400 and dF₂/dP₂=0.48P₂ + 320 The allocation of loads P₁ and P2 between generating units 1 and 2, respectively, for minimum cost of generation to serve a total load of 900 MW, neglecting losses, is

300 MW and 600 MW 400 MW and 500 MW500 MW and 400 MW 200 MW and 700 MW

29➤ The insulation resistance of a cable of length 5 km is 1 M ohm. For a length of 50 km of the same cable, the insulation resistance will be:

1 k ohm1 M ohm0.1 M ohm 1 ohm

30➤ Which among the following is an example for a voltage bidirectional two-quadrant switch?

DiodeMOSFETSCRBJT

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