Certified Flight Instructor - Flight Instructor Airplane Practice Exam

Which statement is true regarding the advantages of aircraft generators and alternators?

1. A generator always provides more current

2. An alternator provides more power at lower RPM

3. A generator charges the battery more effectively

The correct answer is: An alternator provides more power at lower RPM

The correct statement regarding the advantages of aircraft generators and alternators is that an alternator provides more power at lower RPM. This characteristic is significant because it means that alternators can maintain efficient power production even when the aircraft is operating at lower engine speeds, which is particularly important during various phases of flight such as takeoff or slow flight. Alternators are designed to produce alternating current, which can be converted to direct current for battery charging. They typically have a built-in rectifying system that ensures consistent voltage output. This allows them to operate effectively even when the engine RPM is not high, ensuring that the electrical systems of the aircraft can function as required, and the battery can be charged adequately. In contrast, generators generally require a higher RPM to produce significant power, which may limit their efficiency in certain situations. This operational characteristic of alternators makes them more favorable for modern aircraft designs, where consistent electrical output is critical for safety and functionality. The other options do not accurately represent the operational advantages of generators and alternators; therefore, focusing on the alternator's capability to deliver power at lower RPM helps clarify why this statement is true and relevant to aircraft operations.