Transformers Objective Questions: Part-5

Transformers Objective Questions with Answers

[1] In a transformer the energy is conveyed from primary to secondary?
A. Through cooling coil
B. Through air
C. By the flux
D. None of the above

Ans: C

[2] Which loss is not common between a transformer and rotating machines?
A. Eddy current loss
B. Copper loss
C. Windage loss
D. Hysteresis loss

Ans: A

Note: Refer comments for explanation.
[3] No load test on a transformer is carried out to find
A. Copper loss
B. Magnetising current
C. Magnetising current and loss
D. Efficiency of the transformer

Ans:C

[4] Sumpner's test is conducted on transformers to find
A. Temperature
B. Stray losses
C. All-day efficiency
D. None of the above

Ans: A

[5] The efficiency of a transformer will be maximum when
A. Copper losses = hysteresis losses
B. Hysteresis losses = eddy current losses
C. Eddy current losses = copper losses
D. Copper losses = iron losses

Ans: D

[6] The purpose of providing an iron core in a transformer is to
A. Provide support to windings
B. Reduce hysteresis loss
C. Decrease the reluctance of the magnetic path
D. Reduce eddy current losses

Ans: C

[7] The highest voltage for transmitting electrical power in India is
A. 33kV
B. 66kV
C. 132kV
D. 400kV

Ans:D

[8] The function of conservator in a transformer is
A. To protect against internal fault
B. To reduce copper as well as core losses
C. To cool the transformer oil
D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Ans: D

[9] The core used in high frequency transformer is usually
A. Copper core
B. Cost iron core
C. Air core
D. Mid steel core

Ans: C

[10] Cross over windings are used in
A. Low voltage side of high kVA rating transformers
B. Current transformers
C. High voltage side of high kVA rating transformers
D. High voltage side of low kVA rating transformers

Ans: D