ARMATURE REACTION OF GENERATORS

In dc generators, inter-pole field coils are connected on

• in parallel with the load

• in series with the load

• in parallel with the armature winding

• in series with the armature winding

In a lap winding for a 4 pole machine, the number of parallel paths will be

• 15

• 4

• 8

• 2

If 0_mbe the mechanical degrees, 0_ebe the electrical degree and P be the number of poles on a dc generator, then which of the following relations is valid?

• 0_m= 20_eP

• 0_e= 20_mP

• 0_m = 20_e/P

• 0_e = 20_m/P

Which winding on dc generators is preferred for generating large currents?

• Progressive wave winding

• Lap winding

• Reprogressive wave winding

• None of the above

The Effect if Armature Flux on Main field flux is called

The pole shoe of a dc machine is laminated for the purpose of

• decreasing hysteresis loss

• decreasing eddy current loss

• both (A) abs (B)

• none of them

The principle of dc generator is based on

• mutually induced emf

• dynamically induced emf

• self-induced emf

• all of them

The component of a dc generator which plays a vital role in providing direct current is

• brushes

• commutator

• equalizer ring

• dummy coils

A 4-pole dc generator is running at 1500 rpm. The frequency of the current in the armature is

• 60

• 50

• 25

• 100

A Dummy coil in a dc generator is provided to reduce

• tendency for reversal

• armature reaction

• hysteresis losses

• mechanical unbalance