Review Flashcards
What does the symbol ‘K’ stand for in the DC generator voltage formula EG = K × Ф × n?
constant of the machine
What does the symbol ‘Ф’ represent in the DC generator voltage formula EG = K × Ф × n?
field flux
What does the symbol ‘n’ represent in the DC generator voltage formula EG = K × Ф × n?
speed (rotational frequency)
What does the symbol ‘EG’ stand for in the DC generator voltage formula EG = K × Ф × n?
generated voltage
What are the two ways to control the generated voltage in a DC generator?
- Rheostat
- Other method (less practical)
Which method of controlling generated voltage in a DC generator is considered the best?
Rheostat
What are the two magnetic fields interacting in a DC generator under load?
- Main field flux
- Armature field flux
What is the effect of armature reaction on the neutral plane in a DC generator?
The neutral plane shifts in the direction of rotation
The amount that the neutral plane shifts from no load to full load is ______ proportional to armature flux.
directly
What can correct the problem of shifting neutral plane with load in a DC generator?
Moving brushes
What are commutating windings also called?
interpole windings
Commutating windings are constructed of ______ wire.
large
Commutating windings are connected in ______ with the armature.
series
The interpole must have the same polarity as the main pole ______ of it in the direction of rotation.
ahead
What can be used to correct armature reaction in the polar zone?
Compensating windings
Compensating windings run ______ to the armature windings.
parallel
As electrical load is increased on a DC generator, the prime mover will slow down due to what effect?
Motor action (Lorenz Force)
A lamp rated for 120 V, 50 W will produce what wattage if supplied by a 240 V source?
200 W
What happens to total circuit power when the resistance of one of three parallel resistors is decreased?
Increase
