Top 350+ Solved Electrical Machine 1 MCQ Questions Answer
Q. In the transformer the function of a conservator is to
a. provide fresh air for cooling the transformer
b. supply cooling oil to transformer in time of need
c. protect the transformer from damage when oil expends due to heating
d. none of the above
Q. Natural oil cooling is used for transformers upto a rating of
a. 3000 kVA
b. 1000 kVA
c. 500 kVA
d. 250 kVA
Q. Power transformers are designed to have maximum efficiency at
a. nearly full load
b. 70% full load
c. 50% full load
d. no load
Q. The maximum efficiency of a distribution transformer is
a. at no load
b. at 50% full load
c. at 80% full load
d. at full load
Q. Transformer breaths in when
a. load on it increases
b. load on it decreases
c. load remains constant
d. none of the above
Q. No-load current of a transformer has
a. has high magnitude and low power factor
b. has high magnitude and high power factor
c. has small magnitude and high power factor
d. has small magnitude and low powerfactor
Q. Spacers are provided between adjacent coils
a. to provide free passage to the cool¬ing oil
b. to insulate the coils from each other
c. both (a) and (b)
d. none of the above
Q. Greater the secondary leakage flux
a. less will be the secondary induced e.m.f.
b. less will be the primary induced e.m.f.
c. less will be the primary terminal voltage
d. none of the above
Q. The purpose of providing iron core in a step-up transformer is
a. to provide coupling between primary and secondary
b. to increase the magnitude of mutual flux
c. to decrease the magnitude of mag-netizing current
d. to provide all above features
Q. The power transformer is a constant
a. voltage device
b. current device
c. power device
d. main flux device
Q. Two transformers operating in parallel will share the load depending upon their
a. leakage reactance
b. per unit impedance
c. efficiencies
d. ratings
Q. What will happen if the transformers working in parallel are not connected withregard 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 aredifferent, 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 tr
Q. In a transformer the tappings are generally provided on
a. primary side
b. secondary side
c. low voltage side
d. high voltage side