17th
Apr
Three Phase Systems In Power Applications MCQ

Three Phase Systems In Power Applications MCQ

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  • 17th Apr, 2021
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Three Phase Systems In Power Applications MCQ Test

Following are mostly asked Three phase systems in power applications MCQ test that are designed for professionals like you to crack you interviews. You can take this Three phase systems in power applications online test before appearing to you real interview. This Three phase systems in power applications quiz there are around 30+ multiple choice questions on Three phase systems in power applications with four options.

1) In a three phase ac circuit the sum of all three generated voltage is ..........

  • A. One
  • B. Zero
  • C. Infinite
  • D. None of the above

2) For a three-phase full controlled converter with r load, the average value of output voltage is zero for

  • A. α = 90°
  • B. α = 180°
  • C. α = 270°
  • D. α = 360°

3) The power consumed by a three phase load can be determined using the formula .............

  • A. P = √3 V I
  • B. P = 3 V I cos ø
  • C. P = √3 V I sin ø
  • D. None of the above

4) In case of three phase fully controlled converter with 6 scrs commutation occurs every

  • A. 30°
  • B. 60°
  • C. 90°
  • D. 120°

5) In a balanced three-phase load, each phase

  • A. An equal amount of power
  • B. Two-thirds of total power
  • C. A power consumption equal to (√3VL) IL
  • D. None of the above

6) As compared to three phase induction motor the advantage of synchronous Motor in addition to its constant speed is ........

  • A. Better efficiency
  • B. Higher Power factor
  • C. Lower Power factor
  • D. Both Better efficiency & Higher Power factor

7) The most common type of ac motor is the .........

  • A. Single-phase induction motor
  • B. Three-phase induction motor
  • C. Two-phase induction motor
  • D. None of the above

8) Rotor induced EMF is nearly 20% of maximum value.

  • A. True
  • B. False

9) The windings of a three-phase alternator are separated by

  • A. 100º E
  • B. 200º E
  • C. 120º E
  • D. None of the above

10) In a three-phase system, when the loads are perfectly balanced, the neutral current is

  • A. at maximum
  • B. zero
  • C. two-thirds of maximum
  • D. one-third of maximum

11) In a certain three-wire Y-connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages are

  • A. 666 V
  • B. 2,000 V
  • C. 3,464 V
  • D. None of the above

12) Polyphase generators produce simultaneous multiple sinusoidal voltages that are separated by

  • A. Certain constant voltages
  • B. Certain constant currents
  • C. Certain constant phase angles
  • D. None of the above

13) A single-phase sinusoidal voltage of 120 V is connected to a 90 load. Current in the circuit is

  • A. 6.2 A
  • B. 1.33 A
  • C. 13.3 mA
  • D. None of the above

14) A constant load power means a uniform conversion of

  • A. Voltage to current
  • B. Current to voltage
  • C. Electrical to mechanical energy
  • D. None of the above

15) In a -connected generator, all of the phase voltages are

  • A. zero
  • B. one-third of total
  • C. equal in magnitude
  • D. None of the above

16) Choppers converts ...............

  • A. AC to AC
  • B. AC to DC
  • C. DC to DC
  • D. DC to AC

17) Three units of single phase transformers and one single three-phase transformer rating ..............

  • A. May be same
  • B. Can never be made same
  • C. Will be same for one rating
  • D. None of the above

18) Which of the following device perform DC-AC conversion?

  • A. Switch
  • B. Inverter
  • C. Rectifier
  • D. Chopper

19) What is the Syncronous speed of a 3 phase, 4 pole, 50Hz induction motor?

  • A. 1400 rpm
  • B. 1500 rpm
  • C. 3000 rpm
  • D. 2800 rpm

20) What is the Resultant flux of 3 phase induction motor?

  • A. 2 φm
  • B. 3 φm
  • C. (√3/2)φm
  • D. (3/2)φm

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