Three-Phase Systems in Power Applications Online Test – Multiple Choice Questions and Answers 1. In a certain three-wire Y-connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages are 2,000 V 666 V 6,000 V 3,464 V 2. 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 3. In a Y-Y source/load configuration, the phase current, the line current, and the load current are 120° out of phase phase current, the line current, and the load current are all equal in each phase line current and the load current are in phase, and both are out of phase with the phase current phase current and the line current are in phase, and both are 120° out of phase with the load current 4. A constant load power means a uniform conversion of electrical to mechanical energy current to voltage mechanical to electrical energy voltage to current 5. In a Y-connected circuit, the magnitude of each line current is one-third the phase current three times the corresponding phase current equal to the corresponding phase current zero 6. In a Y-connected circuit, between each line voltage and the nearest phase voltage, there is a phase angle of 30° 0° 60° 90° 7. Polyphase generators produce simultaneous multiple sinusoidal voltages that are separated by certain constant voltages certain constant frequencies certain constant currents certain constant phase angles 8. In a three-phase system, when the loads are perfectly balanced, the neutral current is zero two-thirds of maximum one-third of maximum at maximum 9. In a certain Y-Y system, the source phase currents each have a magnitude of 9 A. The magnitude of each load current for a balanced load condition is 3A 12A 9A 27A 10. In a three-phase system, the voltages are separated by 45° 90° 120° 180° Loading … Question 1 of 10
