DC GENERATORS

To increase the speed and hence generated e.m.f.

To reduce the combined effect of armature reaction of both machines

So that two similar machines will pass approximately equal currents to the load

To increase the series flux

So that the two identical machines will pass approximately equal currents to the load

To reduce the combined effect of armature reaction of both the machines

To increase the series flux

To increase the generated e.m.f.

Cast-iron

Copper

Nonferrous material

Silicon steel

Using equalizer rings

Using carbon brushes of superior quality

Using conductor of annealed copper

Using commutator with large number of segments

None of these

Both (A) and (B)

Electromagnets

Permanent magnets