Question

_________ minus freestream static pressure gives freestream dynamic pressure

(a) Stagnation pressure

(b) Total pressure

(c) Fluid pressure

(d) Instantaneous pressure

I had been asked this question during an interview.

Question is taken from Stagnation Properties topic in portion Compressible Flow of Fluid Mechanics

Answer 1

The correct choice is (a) Stagnation pressure

For explanation I would say: Stagnation pressure minus freestream static pressure gives freestream dynamic pressure.  This plays an important role in determining the pressure coefficient. Hence, the pressure coefficient at stagnation points is +1.