ELE290

In delta connected system,

• Line voltage is equal to phase voltage

• Line current is equal to phase current

• Line voltage and line current is zero

• None of the above

The expression for total power output of a delta connected system in terms of phase voltage and current is given by

• √3V_pI_pcos∅

• 3V_pI_pcos∅

• 1/√ 3V_pI_pcos∅

• 1/3 x V_pI_pcos∅

For a star connected three phase AC circuit,

• Line voltage is equal to phase voltage and line current is square root three times the phase current

• Line voltage is square root three times phase voltage and phase current is equal to line current

• Line voltage is equal to phase voltage and line current is equal to phase current

• None of the above

In a balanced three-phase system-delta load, if we assume the line voltage is VRY = V∠0⁰ as a reference phasor. Then the voltage VYB is?

• V∠0⁰

• V∠120⁰

• V∠-120⁰

• V∠240⁰

A three phase, balanced delta connected load of (4+j8) Ω is connected across a 400V, 3 – Ø balanced supply. Determine the phase current IR . Assume the phase sequence to be RYB.

• 44.73∠-63.4⁰A

• 44.73∠63.4⁰A

• 25.82∠-63.4⁰A

• 25.82∠63.4⁰A

Phase voltages of a star connected alternator are VR = 240∠ O° V, VY = 240∠ -120° V & VB = 240 ∠ + 120° V. What is the phase sequence of the system ?

• BRY

• RBY

• YBR

• RYB

In a certain three-wire Y-connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages are

• 2000 V

• 1155 V

• 6000 V

• 3464 V

In a Y-connected circuit, between each line voltage and the nearest phase voltage, there is a phase angle of

• 30°

• 60°

• 90°

• 120°

In a three-phase system, the voltages are separated by

• 45°

• 90°

• 120°

• 180°

If in a delta-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

• 52 V