Polyphase

120

. In a balanced 3-phase voltage generator, the different phase voltages are degrees apart

30

In a balanced 3 phase wye connected system, the line voltage and the corresponding phase voltage are displaced from each other by

1.732 times the phase voltage

In a balanced 3-phase wye connected generator, the line-to-line voltage is

the phasor difference of two-phase voltages

In a balanced three phase star connected system, the line voltage is

equal to the phase current

In a star connected system, the line current is

1.732 times the phase current

In delta connected system, the line current is

leads, lags

In the balanced three-phase ABC system, the line voltage_____________ the phase voltage and the line current____________ the phase current by 30 degrees.

Phase current are changed in angle but not in magnitude

When the phase sequence at the three-phase load is reversed

unequal line voltages across the load

In a three-phase supply floating neutral is undesirable because it gives way to

one

What is the minimum number of wattmeter/s required for measuring power of a three-phase balanced load

Two

What is the minimum number of wattmeter's required to measure unbalanced power of a three-phase system

three

The least number of 1-phase wattmeter required to measure the total power consumed by an unbalance load fed from 3-phase-4-wire system is

1.414x VL x IL x power factor

In a balanced 2-phase system. The total power

The power factor angle of a balanced 3-4 load is the phase angle between

Phase voltage and phase current

The power factor angle of a balanced 3-PHASE load is the phase angle between

30

In three phase wye connected balanced voltage system, the angle between line voltage and phase voltage is, ________degrees.

120

In a balanced 3-phase voltage generator, the different phase voltages are__________ degrees apart

power factor is 0.5

In 2-wattmeter method, the reading in one of the wattmeter will be zero when

power factor 1

In 2-wattmeter method, the reading in one of the wattmeter will be equal when

4-wire star connection

For an unbalance load, which connection is suitable

reactive power

. A wattmeter is installed in a balanced 3-phase system with current coil at line A while voltage coil across B and C. The wattmeter will measure