WorksheetsFAC SERIES EXAMINATION
Total questions: 19
Worksheet time: 25mins
Find power factor of AC circuit which has a resistance of 5 ohm and reactance of 7 ohm. (score 1)
0.71
0.58
0.81
1
Which of the following is not a power factor improvement method. (Score 1)
By static capacitor
synchronous condenser
series inductor
phase advancer
By improving power factor the following effects will occur(score 1) (more than one answer)
Current in the system reduces
Size of cable reduces
System voltage increases
Reactive power increases
The suitable range of power factor is (score 1)
near to zero
near to 0.5
near to unity
near to infinity
Power factor is the ratio of (score 1)
active power/apparent power
reactive power/apparent power
active power/reactive power
apparent power/active power
At resonance power factor of AC series circuit become (score 1)
0
0.5
0.8
1
Find active power in AC circuit with power factor of 0.8 and consumes a current of 5A which is connected across a 230V AC supply (score 1.5)
920
690
1150
1610
Find the power factor of AC circuit which consumes active power of 100 KW and apparent power of 150 KVA. (score 1.5)
0.66
1
0.56
0.74
The phase difference between the phase voltages in a three phase ac supply is (score 1)
110 degree
120 degree
130 degree
90 degree
find line current in star connection if the phase current is 5A (score1)
5
2.88
8.66
0
Find phase voltage of star connection if the line voltage is 415V (score 1)
415
718
239
138
Find active power of star connected system with12ohm impedance in each phase with power factor of 0.8. if the load consumes a line current of 3A.and it is connected to a 415V supply. (Score 2)
1000
1225
2988
1725
The neutral point is available in (score 1)
Star connection
Delta connection
Open delta connection
Either in star or delta
The equation of apparent power in three phase system is (score 1)
3 VphIL
3VLIL
√3 VphIph
3 VphIph
Find resistance in each phase of star connected system with line current of 5A,0.8 pf lagging and it is connected to a 420v ac supply. (score 3)
29.05 ohm
38.8 ohm
48.4 ohm
36.8 ohm
Which statement regarding a star connection is true (score 1)
The end terminal of one winding connected to the starting terminal of other
Phase voltage equal to line voltage
Phase current equal to √3 times line current
The common terminal of windings meet at a common point
How many main fuses on a star connected lighting load system (score 1)
1
2
3
4
Three phase induction motor is self starting because of (score 1)
Rotating magnetic field
pulsating field
phase split
Star connection
Find line current of delta connected system with 9 < 26.56 impedance in each phase which is connected to a 400v ac supply (score 3)
44.4 A
76.9 A
133.19 A
9 A
