Question

What happens to velocity in the converging duct?

(a) Increases

(b) Decreases

(c) Same

(d) Independent

This question was posed to me at a job interview.

This intriguing question originated from Flow of Compressible Fluid through Orifices and Nozzles in chapter Compressible Flow of Fluid Mechanics

Answer 1

Correct choice is (a) Increases

The best explanation: Mass flow rate is given by Q = m/p. This is a relation expressed for mass flow rate. With the presence of a converging duct, the velocity increases. At this point, the area of the duct is less than zero.