WorksheetsThree phase AC
Total questions: 10
Worksheet time: 8mins
A polyphase system is generated by_____
Having two or more generator windings separated by equal electrical angle.
Having generator windings at equal distances
None of the above
A and C
In a three phase AC circuit, the sum of all three generated voltages is ______
Infinite (∞)
Zero (0)
One (1)
none of the above
In a three phase, delta connection ——-
line current is equal to phase current
Line voltage is equal to phase voltage
None of the above
Line voltage and line current is zero
In a Y-connected circuit, the magnitude of each line current is
line current is equal to phase current
Line voltage is equal to phase voltage
None of the above
Line voltage and line current is zero
In a 3 - phase star connected balanced induction motor, the line voltage is equal to the
3 times the phase voltage
√3 times the phase voltage
1/√3 times the phase voltage
1/3 times the phase voltage
Phase voltages of a star connected alternator are ER = 240∠0o V, EY = 240∠-120o V and EB = 240∠ + 120o V. What is the phase sequence of the system?
RYB
RBY
YBR
BYR
In a three-phase system, the voltages are separated by
45°
90°
120°
180°
In a certain three-wire Y-connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages are
2,000 V
6,000 V
666 V
3,464 V
If in a Y-connected ac generator, each phase voltage has a magnitude of 90 VRMS, what is the magnitude of each line voltage?
0 V
90 V
156 V
180 V
In a three-phase system, when the loads are perfectly balanced, the neutral current is
zero
one-third of maximum
two-thirds of maximum
at maximum
