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  1. Energy transfer from primary side of a transformer to its secondary side is done
  2. a) Through air
  3. b) By the flux
  4. c) Though cooling coil
  5. d) None of the above
  6. In a transformer, which of this one does not change?
  7. a) Frequency
  8. b) Voltage
  9. c) Current
  10. d) All of the above
  11. Between a rotating machine and a transformer, name the loss that is uncommon
  12. a) Hysteresis loss
  13. b) Copper loss
  14. c) Eddy current loss
  15. d) Windage loss
  16. Lamination of a transformer core is to
  17. a) Reduce copper losses
  18. b) Reduce hysteresis loss
  19. c) Reduce eddy current losses

d)Reduce all the above losses

  1. What is the percentage of full load current when the transformer draws no load current?
  2. a) 12 to 15 percent
  3. b) 0.2 to 0.5 percent
  4. c) 20 to 30 percent
  5. d) 2 to 5 percent
  6. A transformer’s lamination produces certain degree of mechanical vibrations. What does it depend upon?
  7. a) Size of laminations
  8. b) Gauge of laminations
  9. c) Tightness of clamping

d)all of the above

  1. A transformer’s path of magnetic flux should definitely have
  2. a) Low resistance
  3. b) Low reluctance
  4. c) High resistance

d)High reluctance

  1. The likely chance when a transformer’s lamination has burrs on its edges
  2. a) Noise
  3. b) Vibrations
  4. c) Higher hysteresis loss

d)Higher eddy current loss

  1. In case of transformer oil, its dielectric strength is
  2. a) 100 kV
  3. b) 330 kV
  4. c) 1 kV

d)33 kV

  1. Utilization of no load test which is performed on a transformer is to find out
  2. a) Magnetizingloss and current
  3. b) Efficiency of the transformer
  4. c) Magnetizing current
  5. d) Copper loss
  6. If the consideration is about cold rolled grain oriental steel, its permissible flux density will be
  7. a) 1.7 Wb/m2
  8. b) 2.7 Wb/m2
  9. c) 3.7 Wb/m2
  10. d) 4.7 Wb/m2
  11. On a transformer, Sumpner’s test is done to find out
  12. a) Stray losses
  13. b) All day efficiency
  14. c) Temperature
  15. d) None of the above
  16. A transformer’s efficaciousness will be the highest in
  17. a) Copper losses = Eddy current losses
  18. b) Iron losses = Copper losses
  19. c) Hysteresis losses= Copper losses
  20. d) Eddy current= losses Hysteresis losses
  21. In a certain test performed on a transformer, say short circuit test, it was seen that there was a sudden hike in frequency. It was seen that the hike was from 50 HZ to 200 Hz. What will be the hike by factor (increase) of copper loss?
  22. a) 4
  23. b) 16
  24. c) 1/4
  25. d) 4
  26. Iron core provision in a transformer is for the purpose
  27. a) Decrease the reluctance of the magnetic path
  28. b) Reduce eddy current losses
  29. c) Provide support to windings
  30. d) Reduce hysteresis loss
  31. In transformer, no load current means
  32. a) Lags behind voltage by nearly15°
  33. b) Leads voltage by nearly 15°
  34. c) Lags behind voltage by nearly 75°

d)Leads voltage by nearly 75°

  1. On which side of a transformer is short circuited test performed
  2. a) Primary side
  3. b) Secondary side
  4. c) High voltage side
  5. d) Low voltage side
  6. while installing a transformer, which of this is not the part
  7. Exciter
  8. Buchholz relay
  9. Breather
  10. Conservator
  11. Higher flux density utilization in transformer design
  12. Reduces copper losses
  13. Reduces iron losses
  14. Increases part load efficiency
  15. Reduces weight per kVA
  16. The toppings in any transformer is provided on

Low voltage side

Primary side

High voltage side

Secondary side

  1. In a breather the utilized chemical is
  2. Silica gel
  3. Sodium chloride
  4. Silica sand
  5. Asbestos fibre
  6. The quality breather chemical which is utilized in a transformer should definitely comprise of
  7. Cleansing the transformer oil
  8. Cooling the transformer oil
  9. Absorbing moisture
  10. Ionizing air
  11. In case of ideal transformer, its secondary and primary inductances has unlimited value.

Yes

No

  1. If supply voltage of a pump motor is 1 and 2/3rd of its voltage is what it requires to run, it will
  2. Continue to run at less speed
  3. Burn
  4. Continue to deliver exact power
  5. Stall
  6. Due to the magnetic force creating vibrations of laminations a noise is produced. It is called
  7. Zoom
  8. Magnetostriction
  9. Hum
  10. Boo
  11. Ratingsof an ideal transformer can be stated by
  12. KVA
  13. Volts
  14. KW
  15. Amperes
  16. Transformer core is constructed withcertain materials. The common material is

aluminium

copper

silicon steel

wood

 

 

 

Answers

  1. b
  2. a
  3. c
  4. c
  5. d
  6. d
  7. b
  8. d
  9. d
  10. a
  11. a
  12. c
  13. b
  14. b
  15. a
  16. d
  17. d
  18. a
  19. d
  20. a
  21. a
  22. c
  23. b
  24. d
  25. c
  26. a
  27. b