WorksheetsAC power/Three phase
Total questions: 10
Worksheet time: 4mins
What is the complex power?
power at any instant of time
average of the instantaneous power over one period
product of the rms values of voltage and current
product of rms voltage phasor and the complex conjugate of the rms current phasor
Calculate current (I)
22.3+j1.33 A
0.62+j0.93 A
1.12+0.07 A
0.62-j0.93 A
Reactive power is measured in
watts
VA
VAR
V
In the power triangle shown above, the
reactive power is:
1000 VAR leading
1000 VAR lagging
866 VAR leading
866 VAR lagging
In a Y-connected load, the line current and phase
current are equal.
True
False
In Delta -connected load, the line current and phase
current are equal
True
False
For the power triangle in above, the apparent
power is:
2000 VA
1000 VA
866 VA
500 VA
The instrument for measuring average power is the:
ammeter
voltmeter
wattmeter
varmeter
The average power absorbed by an inductor is zero
True
False
In a Y-Y system, a line voltage of 220 V produces a
phase voltage of:
381 V
311 V
220 V
127 V
