CAGI Compressed Air Specialist Practice Exam 2025 – Your All-In-One Guide to Master the Certification!

The statement accurately reflecting the impact of pipe diameter on air velocity is that a larger diameter reduces the velocity of the air flowing through it. When air moves through a pipe, the velocity is inversely related to the cross-sectional area of the pipe. In a larger diameter pipe, the increased cross-sectional area allows for more air to flow, but the velocity of the air decreases. This principle is derived from the continuity equation in fluid dynamics, which maintains that the product of the cross-sectional area and the velocity remains constant for steady flow of an incompressible fluid.

In a smaller diameter pipe, there is less area for the air to move through, so the velocity increases as the same volume of air must pass through a tighter space, resulting in faster movement. Therefore, as the pipe diameter increases, the velocity of the air decreases, reflecting the correct nature of the relationship between diameter and velocity in fluid dynamics.

Other statements do not accurately describe this relationship. The idea that changing diameter has no effect on velocity contradicts basic principles of fluid flow, and stating that velocity doubles with increased diameter misinterprets the relationship between cross-sectional area and flow velocity.