Home » Transfomer -1 » Top 100 MCQ Transformer questions and answers

Top 100 MCQ Transformer questions and answers


& Others competitive]

91. The efficiency of a transformer, under heavy loads, is comparatively low because

(a) copper loss becomes high in proportion to the output

(b) iron loss is increased considerably

(c) voltage drop both in primary and secondary becomes large

(d) secondary output is much less as compared to primary input

Ans: a

92. An open-circuit test on a transformer is conducted primarily to measure

(a) insulation resistance

(b) copper loss

(c) core loss

(d) total loss


Ans: c

93. A no-load test is performed on a transformer to determine

(a) core loss

 (b) efficiency

(c) magnetising current

(d) magnetising current and loss

Ans: d

94. The voltage transformation ratio of a transformer is equal to the ratio of

(a) primary turns to secondary turns

(b) secondary current to primary current

(c) secondary induced e.m.f. to primary induced e.m.f.

(d) secondary terminal voltage to primary applied voltage

Ans: c

95. Part of the transformer which is most subject to damage from overheating is

(a) iron core

(b) copper winding

(c) winding insulation

(d) frame or case

Ans: c

96.For a transformer, operating at constant load current, maximum efficiency will occur at …

(a) 0.8 leading power factor

(b) 0.8 lagging power factor

(c) zero power factor

(d) unity power factor

Ans: d

97. Which of the following protection is normally not provided on small distribution transformers?

(a) Over fluxing protection

(b) Buchholz relay

(c) Overcurrent protection

(d) All of the above

Ans: b

98.Which of the following acts as a protection against high voltage surges due to lightning and switching?

(a) Horn gaps

(b) Thermal overload relays

(c) Breather

(d) Conservator

Ans: a

99.The efficiency of two identical transformers under load conditions can be determined by

(a) short-circuit test

(b) back-to-back test

(c) open circuit test

(d) any of the above

Ans: b

100.Which of the following insulating materials can withstand the highest temperature safely?

(a) Cellulose

(b) Asbestos

(c) Mica

(d) Glass fibre

Ans: c


 All the best for competitive Exam.

If You Want More Questions Then Click Below

1 2 3 4 5 6 7 8 9 10

ISRO Previous Years Question paper pdf technician- B (electrician)

Question Papers pdf  in Hindi & English language (ITI Electrical) 

Anyone want to buy full question sets so click below link . In this pdf file to developed

Previous Years Question Paper
      MRP: Rs. 50  Buy Now


Leave a comment

Your email address will not be published.

FREE Physics Mock Test for all gov. exam [Specially RRB - Group D, NTPC,RRB JE, ALP , Constable]
FREE Biology Mock Test for all gov. exam [Specially RRB - Group D, NTPC,RRB JE, ALP , Constable]
Free Electrical Mock test 2021 for all Gov. Exam, Module
Electronics Mock test 2021 for all Gov. Exam

Join Our Social Medium Platform

error: Content is protected !!