Basic Electrical Engineering (3110005) MCQs

MCQs of Transformers

Showing 11 to 20 out of 31 Questions
11.
Three units of single phase transformers and one single three-phase transformer rating
(a) will be same for one rating
(b) can never be made same
(c) may be same
(d) none of the mentioned
Answer:

Option (a)

12.
The transformer which is more feasible to use in the distribution ends should be
(a) star-delta
(b) delta-star
(c) scott
(d) delta-delta
Answer:

Option (b)

13.
Shape of emf generated by delta connected transformer is not always sinusoidal.
(a) True
(b) False
Answer:

Option (b)

14.
The statements which support the points that auto transformers are advantageous I. Weight of conductor reduces II. Ohmic losses reduces III. Leakage reactance reduces IV. Lower short-circuit current
(a) I,II,III
(b) II,III,IV
(c) I,II,III,IV
(d) IV
Answer:

Option (a)

15.
Maximum efficiency of a transformer for a constant load current , occurs at
(a) at any p.f
(b) zero p.f leading
(c) zero p.f lagging
(d) unity p.f
Answer:

Option (d)

16.
The tappings on the transformers is provided on
(a) h.v side at one end of the winding
(b) l.v. side at one end of the winding
(c) h.v side at middle
(d) l.v side at middle
Answer:

Option (c)

17.
Which of the following loss varies with the load
(a) hystresis loss
(b) eddy current loss
(c) copper loss
(d) core loss
Answer:

Option (c)

18.
At light load transformer efficiency is less because
(a) secondary output is low
(b) transformer losses are high
(c) fixed loss is high compared to output
(d) copper loss is small
Answer:

Option (c)

19.
Material commonly used in making transformer core is
(a) cast iron
(b) mild steel
(c) high silicom steel
(d) high carbon steel
Answer:

Option (c)

20.
Main advantage of auto transformer over two windings transformer is that
(a) it needs no cooling
(b) it uses only one winding
(c) core losses are reduced
(d) it has simple construction
Answer:

Option (b)

Showing 11 to 20 out of 31 Questions