Unit 21 Flashcards
The rotor of an ac generator contains the ________ field, which develops the magnetic flux lines
Electromagnetic
The current used for the field winding is called the ____ ____
Excitation current
Direct-current generators require a _____ field to induce voltage in the rotating armature to create current flow
Magnetic
When the generator supplies the excitation current it is called what?
Self-excited generator
If a separate dc power source is used to supply the excitation field, the generator is called what?
Separately excited generator
There are six leads from the windings of a three-phase generator which can be connected in ____ for delta connections or in _____ for wye connections
Series ; Parallel
In an ac generator the magnetic lines of force from the rotor electromagnet are made to cut through the stationary conductor coils. The relative motion between the lines of force and the conductor coils produces an ______ force in the conductors
Electromotive
Three-phase ac generators have three equally spaced windings, all _____ degrees out-of-phase with each other
120
If the magnetic field is created by an electromagnet, the electromagnetic field is called what?
Field winding
