DC Generator

The armature of dc generator is laminated to

• Reduce bulk

• reduce eddy current loss

• increase strength of machine

• reducing the Noise

Brushes of DC machine is made up of

• Carbon

• soft copper

• Hard copper

• All the Above

For High current low voltage applications,..................winding is preferred in armature of dc machine.

the function of pole shoe in a dc generator is

• to reduce the reluctance of magnetic flux path

• to spread out the flux to achieve uniform flux density

• to support the field coils

• all the above

the function of interpoles in a dc generator are:

• neutralize the cross magnetizing effect

• Neutralize commutated self induced emf

• Neutralize both armature reaction flux and commutated self induced emf

• None of the above

The emf induced in a shunt generator is 600V. the armature resistance is 0.1 ohm. If the armature current is 200A, the terminal voltage will be........

• 640 V

• 620 V

• 600 V

• 580 V

In a Dc shunt generator, the critical resistance refers to the resistance of .......

• Brushes

• Armature

• Field

• Load

For arc welding, which dc generator is prefered.

• DC series generator

• Cumulative compound generator

• Differential compound generator

• dc shunt generator

A 4 pole generator, having wave-wound armature winding has 51 slots each contains 20 conductors. What will be the voltage generated in the machine when driven at 1500 rpm assuming the flux per pole to be 7 mWb ?

External characteristics is the graph between terminal voltage and load current of a dc generator.

• True

• False