Final answer:
The statement regarding the ignition armature ground circuit causing trouble is true, as a proper earth or ground connection is essential for the ignition system's functionality and safety.
Step-by-step explanation:
The statement about the ignition armature ground circuit potentially causing trouble is true. In an ignition system, particularly in engines, the armature lamination stack is part of the magneto that generates the high voltage needed for the spark plug. A ground circuit issue between the armature lamination stack and the spark plug can indeed cause malfunctions in the ignition process. A proper earth or ground connection is crucial for safety and the correct operation of electrical devices, as represented in figures where a broken ground connection can lead to severe electric shocks, while a proper ground triggers a circuit breaker to trip in the event of a fault.