FAA Powerplant Written Practice Test

Which materials are predominantly used as conductors in aircraft applications?

1. Gold and silver

2. Iron and copper

3. Copper and aluminum

4. Aluminum and plastic

The correct answer is: Copper and aluminum

Copper and aluminum are predominantly used as conductors in aircraft applications due to their excellent electrical conductivity and favorable physical properties. Copper is known for its high conductivity, ductility, and resistance to corrosion, making it ideal for wiring and electrical connections in various aircraft systems. It allows for efficient power transmission and minimizes energy loss, which is crucial in aviation where reliability and performance are paramount. Aluminum is also favored for its lightweight properties, which is essential in the aerospace industry. Reducing weight contributes to improved fuel efficiency and overall aircraft performance. While aluminum does not conduct electricity as efficiently as copper, it is still widely used in larger conductor applications, such as in airplane frames and electrical bus bars, where weight savings can have a significant impact. The combination of these two materials effectively meets the demands of electrical systems in aircraft, balancing conductivity with weight considerations, which is essential in the design and operation of modern aircraft.