Q.1
What is Transformer?
  • a) Transformer is a device used to convert low alternating voltage to a high alternating voltage
  • b) Transformer is a device used to convert alternating current to direct current
  • c) Transformer is a device used to convert low alternating current to a high alternating current
  • d) Transformers are used only for low alternating voltage
Q.2
What is the function of a transformer?
  • a) Transformer is used to step down or up the AC voltages and currents
  • b) Transformer is used to step down or up the DC voltages and currents
  • c) Transformer converts DC to AC voltages
  • d) Transformer converts AC to DC voltages
Q.3
What is the working principle of a Transformer?
  • a) Transformer works on the principle of self induction
  • b) Transformer works on the principle of mutual induction
  • c) Transformer works on the principle of ampere law
  • d) Transformer works on the principle of coulomb law
Q.4
Transformer ratings are given in _____________
  • a) kVA
  • b) HP
  • c) kVAR
  • d) kW
Q.5
What is the current transformer?
  • a) transformer used with an A.C. voltmeter
  • b) transformer used with an A.C. ammeter
  • c) transformer used with an D.C. voltmeter
  • d) transformer used with an D.C. ammeter
Q.6
Current transformers are __________________
  • a) parallel connected type of instrument transformers
  • b) series connected type of instrument transformers
  • c) parallel connected normal transformers
  • d) series-parallel connected type of instrument transformers
Q.7
Which of the following is not a part of transformer installation?
  • a) Breather
  • b) Conservator
  • c) Exciter
  • d) Buchholz relay
Q.8
Transformer core is generally made of ___________
  • a) Cannot be determined
  • b) Can be made with any of the above method
  • c) By stacking large number of sheets together
  • d) Single block of core material
Q.9
The purpose of the transformer core is to provide ____________
  • a) Low reluctance path
  • b) High inductive path
  • c) High capacitive path
  • d) High reluctance path
Q.10
Transformers are generally designed for ___________
  • a) one-time use
  • b) off-site problem solving
  • c) short-time use
  • d) on-site problem solving
Q.11
What is the thickness of laminations used in a transformer?
  • a) 14 mm to 15 mm
  • b) 25 mm to 40 mm
  • c) 0.1 mm to 0.5 mm
  • d) 4 mm to 5 mm
Q.12
Which type of flux does transformer action need?
  • a) Alternating electric flux
  • b) Alternating magnetic flux
  • c) Increasing magnetic flux
  • d) Constant magnetic flux
Q.13
Primary winding of a transformer ______________
  • a) Could either be a low voltage or high voltage winding
  • b) Is always a high voltage winding
  • c) Cannot be determined
  • d) Is always a low voltage winding
Q.14
Which of the following transformer, Buchholz’s relay can be fixed on?
  • a) Welding transformers
  • b) Oil cooled transformers
  • c) Auto-transformers
  • d) Air-cooled transformers
Q.15
What is the function of a breather in a transformer?
  • a) To arrest flow of moisture when outside air enters the transformer
  • b) To cool the transformer oil
  • c) To provide oxygen inside the tank
  • d) To cool the coils during reduced load
Q.16
An ideal transformer will have maximum efficiency at a load such that _____________
  • a) copper loss > iron loss
  • b) cannot be determined
  • c) copper loss = iron loss
  • d) copper loss < iron loss
Q.17
Which transformer insulation material is best compare to Kraft paper?
  • a) Asbestos
  • b) Oil
  • c) Cotton
  • d) Low grade pressboard
Q.18
For a transformer with primary turnssecondary turnsifcurrent is flowing through primary, we will get ___________
  • a) 800A at secondary
  • b) 40A at secondary
  • c) 80A at secondary
  • d) 5A at secondary
Q.19
AKVA transformer is constructed to a turns ratio of N1/N2 =The impedance of primary winding is 3+j5 ohms and of secondary winding is 0.5+j0.8 ohms. What will be the impedance of transformer when referred to primary?
  • a) 53 + 85j ohms
  • b) 53j + 85 ohms
  • c) Can’t be calculated
  • d) 3.5 + 5.8j ohms
Q.20
The full-load copper loss of a transformer isW. At half-load, the copper loss will be _______
  • a) 1600 W
  • b) 6400 W
  • c) 400 W
  • d) 800 W
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