Induced drag is best described as:

• A. The undesirable but unavoidable byproduct of lift.
• B. Drag caused by airflow separation at high speed.
• C. Drag from engine power losses.
• D. Drag that increases with air density.

Answer: (A)

Induced drag arises directly from the way a wing generates lift. When lift is produced, the airflow must be redirected downward behind the wing, creating wingtip vortices and a downward component of flow called downwash. This downwash interacts with the flight path to produce a rearward force component, which we experience as drag. Since this drag is an inevitable consequence of producing lift with a finite wing, it’s best described as an undesirable but unavoidable byproduct of lift. It’s most noticeable at lower speeds and higher angles of attack and decreases as speed increases.

Other options miss the key point: drag due to airflow separation at high speed is parasite drag, not the lift-related drag; drag from engine power losses is tied to propulsion, not the lift-generated portion; and drag that increases with air density is not the defining feature of induced drag.