1. The short circuit characteristic of an alternator is:
a) always linear
b) always non-linear
c) either (a) and (b)
d) none of the above
2. Regulation of an alternator supplying resistive or inductive load is:
a) always positive
b) always negative
c) either of the above or zero
d) none of the above
3. Synchronous reactance of an alternator is due to:
a) leakage flux only
b) reactance because of armature reaction in the machine
c) synchronous machine reactance
d) both, leakage flux as well as armature reaction
4. In synchronous generator, the effect of cross magnetization is to make the generated voltage:
a) truely sinusoidal
b) non sinusoidal
c) free from harmonics
d) none of the above
5. In an alternator, reactance emf
a) leads the current by 90 deg
b) lags behind the current by 90 deg
c) is in phase with the current
d) none of the above
6. In an alternator, the armature reaction is considered to be equivalent to a fictitious:
a) reactance
b) resistance
c) impedance
d) admittance
7. The seventh space harmonics in the mmf produced by balanced fundamental frequency armature currents rotate at __ times the synchronous speed with respect to the field:
a) 5/7
b) 8/7
c) 6/7
d) 7/6
8.The maximum current that can be supplied by an alternator depends on:
a) exciter current
b) exciter voltage
c) strength of magnetic filed
d) number of poles
a) always linear
b) always non-linear
c) either (a) and (b)
d) none of the above
2. Regulation of an alternator supplying resistive or inductive load is:
a) always positive
b) always negative
c) either of the above or zero
d) none of the above
3. Synchronous reactance of an alternator is due to:
a) leakage flux only
b) reactance because of armature reaction in the machine
c) synchronous machine reactance
d) both, leakage flux as well as armature reaction
4. In synchronous generator, the effect of cross magnetization is to make the generated voltage:
a) truely sinusoidal
b) non sinusoidal
c) free from harmonics
d) none of the above
5. In an alternator, reactance emf
a) leads the current by 90 deg
b) lags behind the current by 90 deg
c) is in phase with the current
d) none of the above
6. In an alternator, the armature reaction is considered to be equivalent to a fictitious:
a) reactance
b) resistance
c) impedance
d) admittance
7. The seventh space harmonics in the mmf produced by balanced fundamental frequency armature currents rotate at __ times the synchronous speed with respect to the field:
a) 5/7
b) 8/7
c) 6/7
d) 7/6
8.The maximum current that can be supplied by an alternator depends on:
a) exciter current
b) exciter voltage
c) strength of magnetic filed
d) number of poles
