3 phase AC system

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

• 1 & 2

In a three phase AC circuit, the sum of all three generated voltages is _______ ?

• Infinite (∞)

• Zero (0)

• One (1)

• None of the above

For a star connected three phase AC circuit ———

• Phase voltage is equal to line voltage and phase current is three times the line current

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

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

  None of the above

• None of the above

In a three phase, delta connection ——-

• line current is equal to phase current

• Line voltage is equal to phase voltage

• Line voltage and line current is zero

• None of the above

What is value of angle difference between the phases in a 3 phase system?

• -120

• +120

• -240

• All of the above

What do you mean by phase sequence

• It is a time order of voltage passing

• It is a sequence of conductors

• It is a sequence of power

• None of the above

In a Y-Y system, a line voltage of 220V produces a phase voltage of:

• 381 V

• 311 V

• 220 V

• 156 V

• 58 V

• 71 V

• 100 V

• 141 V

• abc

• acb

• bbc

• caa

Power in a Three Phase Circuit = _________.

• P = 3 V_Ph I_Ph CosФ

• P = √3 V_L I_L CosФ

• Both 1 & 2.

• None of The Above