WorksheetsQuiz 2 (AC Machines)
Total questions: 12
Worksheet time: 22mins
A 3-phase Alternator has a rating has a rating of 5000 KVA at 13200 volts. Calculate the full-load Line current.
218.7 A
300 A
419.8 A
500 A
The voltage of an alternator rises from 460 volts at Full-load to 535 volts at no-load. Calculate the % Regulation.
16.3%
14.2%
15.9%
20.5%
A 144 slot stator has a whole coiled 12-pole, 3-phase winding. Calculate the number of coils per group
48 coils per group
50 coils per group
4 coils per group
10 coils per phase
No-load test on a transformer is carried out to determine ________________
Magnetizing current
Copper loss
Magnetizing current and no-load loss
Efficiency of the transformer
Transformers are rated in KVA instead of KW because ________________
Load power factor is often not known
KVA is fixed whereas KW depends on load power factor
Total transformer loss depends on volt-ampere
t has become customary
Which of the following is not a basic element of transformer? _____________
Core
Primary Winding
Secondary Winding
Mutual Flux
In an open circuit test VO is found to be 200 volts. The No load current is found to be 0.7 A and the Core loss is 70 W. The power factor will be_______________
0.5
0.1
0.15
0.2
A 72 slot stator has a half coiled, 4 pole, 3 phase winding. How many coils are there per phase?_______________
3 coils per phase
6 coils per phase
9 coils per phase
12 coils per phase
In an open circuit test VO is found to be 200 volts. The No load current is found to be 0.7 A and the Core loss is 70 W. The No load resistance of the Transformer will be ________
300.5214 Ohms
574.2365 Ohms
571.4286 Ohms
371.4286 Ohms
A 56 pole Alternator is operated at 200 RPM, what frequency is generated?
30 cyles
60 cyles
90 cyles
120 cycles
A 72 slot stator has a half coiled, 4 pole, 3 phase winding. How many coils are there per group?_______________
3 coils per group
6 coils per group
9 coils per group
12 coils per group
A 144 slot stator has a whole coiled 12-pole, 3-phase winding. Calculate the number of coils per phase
48 coils per phase
50 coils per phase
12 coils per phase
10 coils per phase
