Top 80+ Solved Transformers MCQ Questions Answer
Q. In a given transformer for given applied voltage, losses which remain constantirrespective of load changes are
a. friction and windage losses
b. copper losses
c. hysteresis and eddy current losses
d. none of the above
Q. The no load current in a transformer lags behind the applied voltage by an angle ofabout
a. 180°
b. 120"
c. 90°
d. 75°
Q. What will happen if the transformers working in parallel are not connected with regard to polarity ?
a. The power factor of the two trans-formers will be different from the power factor of common load
b. Incorrect polarity will result in dead short circuit
c. The transformers will not share load in proportion to their kVA ratings
d. none of the above
Q. Ifthe percentage impedances of the two transformers working in parallel are different, then
a. transformers will be overheated
b. power factors of both the trans-formers will be same
c. parallel operation will be not possible
d. parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load
Q. An ideal transformer has infinite values of primary and secondary inductances. Thestatement is
a. true
b. false
c. none
d. none
Q. The noise resulting from vibrations of laminations set by magnetic forces, is termed as
a. magnetostrication
b. boo
c. hum
d. zoom
Q. Hysteresis loss in a transformer varies as CBmax = maximum flux density)
a. Bmax
b. Bmax1-6
c. Bmax1-83
d. B max
Q. Material used for construction of transformer core is usually
a. wood
b. copper
c. aluminium
d. silicon steel
Q. The thickness of laminations used in a transformer is usually
a. 0.4 mm to 0.5 mm
b. 4 mm to 5 mm
c. 14 mm to 15 mm
d. 25 mm to 40 mm
Q. The function of conservator in a transformer is
a. to project 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 sur-roundings
Q. The highest voltage for transmitting electrical power in India is
a. 33 kV.
b. 66 kV
c. 132 kV
d. 400 kV
Q. In a transformer the resistance between its primary and secondary is
a. zero
b. 1 ohm
c. 1000 ohms
d. infinite
Q. A Buchholz relay can be installed on
a. auto-transformers
b. air-cooled transformers
c. welding transformers
d. oil cooled transformers