DC generator

DC Generators works on the principle of

• Lenz's law

• Lorentz Law

• ohm's law

• Faraday's law of ElectromagneticInduction

Which part converts AC into DC in the DC generator?

• yoke

• Brush

• armature

• commutator

This is a....................DC generator

• shunt

• Seperately Excited

• series

• compound

Armature reaction can be reduced using

• compensating winding

• Interpoles

• equaliser rings

• brush

Open circuit charcteristics shows the relation between ................

• Eo and If

• V and If

• Ia and If

• V and IL

what is the condition for maximum efficiency in DC machine?

• variable loss = constant loss

• E = V

• copper loss = core loss

• mechanical loss = copper loss

which of the following are the effects of armature reaction?

• demagnetisation

• cross magnetisation

• brush shift

• high efficiency

• increased voltage

critical resistance of a DC generator is the ................................... at which the generator will just excite.

• maximum field resistance

• minimum field resistance

• maximum armature resistance

• minimum armature resistance

A 6 pole wave connected DC armature has 250 conductors ad runs at 1200 rpm The emf generated is 600V. The useful flux per pole is

• 0.04 Wb

• 0.4 Wb

• 4.0 Wb

• 0.44 Wb

In DC generator, the characteristic which gives relation between the terminal voltage and the load current is called

• external characteristic

• internal characteristic

• open circuit characteristic

• armature characteristic