Final answer:
A short (grounded) circuit between the right magneto primary and the ignition switch during a magneto check at 1,700 RPM would show no RPM drop when the right magneto is switched off. The expected readings are BOTH: 1,700 RPM, R: 1,700 RPM, L: less than 1,700 RPM, OFF: 0 RPM.
Step-by-step explanation:
When discussing a magneto check at 1,700 RPM, the student is specifically referring to a procedure commonly conducted in aviation to assess the health of an aircraft's magneto systems. A magneto is an electrical generator that creates high voltage for spark plugs which ignites the fuel-air mixture in an aircraft's engine. During a magneto check, the pilot looks for a drop in RPM (revolutions per minute) as individual magnetos are tested. A short (grounded) circuit between the right magneto primary and the ignition switch would result in no RPM drop when the right magneto is switched off, since it would not be contributing to the engine's operation even when switched on. Therefore, we would expect to see: BOTH: 1,700 RPM, R: 1,700 RPM, L: (an RPM value less than 1,700, depending on the usual drop), OFF: 0 RPM. A magneto check ensures both the primary and backup ignition systems are operating properly for safe flight. An absence of RPM drop on one side indicates that the associated magneto is not functioning as there is no change when it is theoretically isolated, possibly due to a grounded circuit.