11- Temperature rise in a transformer is directly proportional to the
(A) apparent power
(B) active power
(C) leakage reactance
(D) none of the above
12- The primary current in a current transformer is dictated by
(A) the secondary burden
(B) the core of the transformer
(C) load current
(D) load voltage
13- In a transformer, the chemical used in the breather is
(A) silica sand
(B) sodium chloride
(C) asbestos fibre
(D) silica gel
14- When the load on the transformer is increased, the eddy current
(A) is increased
(B) remains unchanged
(C) is decreased
(D) becomes zero
15- In Scott connection, the teaser transformer operates on 0.866 of its rated
(A) voltage
(B) impedance
(C) current
(D) power
16- In an autotransformer, the primary and secondary are
(A) only magnetically coupled
(B) only electrically coupled
(C) magnetically as well as electrically
(D) not coupled at all
17- Which relay is used to detect and protect the transformer against incipient faults?
(A) Buchholz relay
(B) Overcurrent relay
(C) Thermal relay
(D) Differential relay
18- The primary and secondary winding induced EMFs E1 and E2 in a two winding transformer are always
(A) in phase opposition with each other
(B) in phase with each other
(C) equal in magnitude
(D) depends on load conditions
19- In the protection of transformer, harmonic restraint is used to guard against
(A) magnetizing inrush current
(B) unbalanced operation
(C) lightning
(D) switching over voltage
20- Burden on the current transformer is usually expressed in terms of
(A) amperes
(B) volts
(C) voltamperes
(D) kilowatt
ANSWERS:
11-(A), 12-(C), 13-(D), 14-(B), 15-(A), 16-(C), 17-(A), 18-(B), 19-(A), 20-(C)