A1. Magnetic induction.
A2. The left-hand rule for generators.
A3. To conduct the currents induced in the armature to an external load.
A4. No flux lines are cut.
A5. A commutator
A6. The point at which the voltage is zero across the two segments.
A7. Two.
A8. Four
A9. By varying the input voltage to the field coils.
A10. Improper commutation.
A11. Distortion of the main field due to the effects of armature current.
A12. To counter act armature reaction.
A13. A force which causes opposition to applied turning force.
A14. Resistance in the armature coils, which increases with temperature.
A15. By laminating the core material.
A16. Drum-type armatures are more efficient, because flux lines are cut by both sides of each coil.
A17. Higher load currents are possible.
A18. Series-wound, shunt-wound, and compound-wound.
A19. Output voltage varies as the load varies.
A20. Voltage regulation.
A21. Parallel operation.
A22. It can serve as a power amplifier.
A23. Gain = output ÷ input.
A24. The mechanical force applied to turn the amplidyne, and the electrical input signal.