What is transmitted from the tachometer generator to the tachometer (RPM) indicator?

• A. A signal for temperature measurement
• B. An electrical reference signal for RPM
• C. Fuel flow data
• D. An oil pressure alert

Answer: (B)

The tachometer generator measures the rotational speed of the engine or motor and converts that mechanical motion into an electrical signal. This electrical reference signal is proportional to the revolutions per minute (RPM) of the engine. The tachometer then receives this signal to accurately display the current RPM on the indicator.

This process allows the tachometer to function as a reliable tool for monitoring engine performance, providing essential information for pilots and crew regarding engine operation. The strength of the electrical signal is directly related to the speed at which the engine is rotating, thus enabling precise measurements.

The other options do not accurately reflect what the tachometer generator transmits: temperature measurement relates to thermocouples or temperature sensors, fuel flow data is specific to fuel management systems, and oil pressure alerts are generated by pressure sensors monitoring the lubrication system, none of which pertain to engine RPM measurement.