60-80%

75-85%

80-90%

85-95%

to avoid unequal distribution of current at the brushes

to help in reducing sparking

both the above

none of the above

1/2 of the original length

1/3 of the original length

3/4 of the original length

2/3 of the original length

2 amps

4 amps

10 amps

20 amps

same kilowatt output ratings

drooping voltage characteristics

same percentage regulation

same no load and full load speed