In the expression of pressure thrust, what does the area (A) represent?

A)
The cross-sectional area of the throat
B)
The cross-sectional area of the nozzle exit
C)
The total surface area of the rocket casing
D)
The total surface area of the combustion chamber

Correct Answer :   The cross-sectional area of the nozzle exit


Explanation : Area (A) represents the nozzle exit cross-sectional area. The expression for pressure thrust is (Pe-Pa)A, where Pe is the exit pressure and Pa is the ambient pressure.