A1. A conductor and a magnetic field.
A2. Armature.
A3. Rotating armature and rotating field.
A4. Output voltage is taken directly from the armature (not through brushes or slip rings).
A5. To provide dc current for the rotating field.
A6. Kilovolt-amperes (volt amperes).
A7. Steam turbine.
A8. Internal combustion engines, water force and electric motors.
A9. One voltage (one output).
A10. In series.
A11. Placement of armature coils.
A12. Three.
A13. C is 1.414 times greater than A or B.
A14. Each phase is displaced 120 from the other two.
A15. Wye and Delta.
A16. Three single-phase, delta-delta, step-down transformers.
A17. Speed of rotation and number of poles.
A18. 120 Hz.
A19. Voltage regulation. As a percentage.
A20. By varying the voltage applied to the field windings.
A21. Output voltage, frequency, and phase relationships.