Two main categories of drag are which of the following?

• A. Induced drag and parasite drag
• B. Interference drag and form drag
• C. Skin friction drag and form drag
• D. Lift and weight

Answer: (A)

Drag in flight falls into two broad groups: induced drag and parasite drag. Induced drag comes from the lift the wing generates; as the wing pushes air to create lift, energy goes into forming wingtip vortices, so some of the thrust is spent against this drag. This type is tied to how much lift you’re producing, and it’s more pronounced at lower speeds when a higher angle of attack is needed. Parasite drag is everything else that doesn’t help with lift, and it grows with speed. It includes form drag (pressure differences around the aircraft), skin friction drag (air slipping along surfaces), and interference drag (airflow interaction where surfaces meet).

So the two main categories are induced drag and parasite drag. The other options mix individual components of parasite drag (like skin friction or form drag) or place forces that aren’t drag into the category (lift and weight), which aren’t a pair of drag categories.