Chapter 7 - Electrical Theory & DC Machines Flashcards
In a shunt motor, torque is proportional to?
Armature current
What controls the excitation of the shunt field?
Regulating rheostat
Flemings “Right Hand” rule in a generator refers to the direction of what?
induced EMF
Electromotive Force abbreviated;
EMF
The end shield of a DC generators holds the ______ .
Bearing housings
What represents the practical unit for resistance (R)?
Ohm
In a DC machine, interpoles carry ______ current
Armature
Free valence electrons when connected to a battery flow towards which pole; Positive or Negative pole.
Positive pole
Since the flux of a shunt motor remains constant, its torque is proportional to armature _______ .
Current
Speed control is usually restricted to which to types of motors?
Shunt & Compounded
The behavior of the separately excited generator is that as load increases, its delivery voltage slightly _____.
Falls
The emf induced in a moving conductor depends on the speed of the moving _______ .
Conductor
Where a high starting torque is required, but the running load may be small, the best DC motor to use would be the _____ motor.
Compound
Armature reaction _____ the main field of a generator.
Distorts
The armature core in a DC machine is made of soft _____ laminations.
Iron
