Following are important objective questions useful for TSSPDCL – Junior Linemen written exams to be conducted in Telangana State. The questions are from the chapter Transformers and in ITI standard. Candidates can avail more questions and online exams through our mock test packages. See model questions below:
The main purpose of using core in transformer is to
A. Decrease reluctance of the common magnetic circuit
B. Decrease iron losses
C. Prevent hysteresis loses
D. Prevent eddy current losses
ANSWER: A
Transformer works on the principle of
A. Self induction
B. Mutual induction
C. Faraday’s law of electromagnetic induction
D. Self and mutual induction both
ANSWER: D
If dc voltage is applied to the primary of a transformer it may
A. Work
B. Burn the winding
C. Not work
D. Give lower voltage on the secondary side
ANSWER: B
Which of the following will improve the mutual coupling between primary and secondary of a transformer ?
A. Transformer oil of high breakdown voltage
B. Winding material of high resistivity
C. High reluctance magnetic core
D. Low reluctance magnetic core
ANSWER: D
Which type of core is used for a high-frequency transformer
A. Open iron core
B. Air core
C. Closed iron core
D. None of these
ANSWER: B
Transformer oil used in transformer provides
A. Insulation and cooling
B. Cooling and lubrication
C. Lubrication and insulation
D. Insulation, cooling and lubrication
ANSWER: A
Enamel layer is coated over the lamination of a transformer core to
A. Attain adhesion between the lamination
B. Prevent corrosion of laminations
C. Decrease the hum
D. Insulate the lamination from each other
ANSWER: D
The primary and secondary induced emfs E1and E2 in two-winding transformer are always
A. Antiphase with each other
B. In phase with each other
C. Equal in magnitude
D. Determined by load on transformer secondary
ANSWER: B
An step-up transformer increases
A. Current
B. Frequency
C. Voltage
D. Power
ANSWER: C
Eddy current losses in a transformer core may be reduced by
A. Reducing the air gap in the magnetic circuit
B. Reducing the thickness of lami-nations
C. Increasing the thickness of lami-nations
D. Increasing the gap in the magnetic circuit
ANSWER: B
In a transformer, the oil must be free from
A. sulphur
B. odour
C. moisture
D. both A and C
ANSWER: D
In a transformer, the magnetic coupling between the primary and secondary circuit can be increased by
A. increasing the number of turns
B. using soft material for winding
C. using magnetic core of low reluc-tance
D. using transformer oil better quality
ANSWER: C
If the density in the core of a transformer is increased
A. the frequency the secondary winding voltage increases
B. waveshape of the secondary winding voltage gets distorted
C. size of the transformer can be reduced
D. eddy current losses increase
ANSWER: C
The power factor in a transformer
A. is always unit
B. is always leading
C. is always lagging
D. depends on the power factor of load
ANSWER: D