Dial pressure test gauges used in power boiler hydrostatic testing should preferably have dials graduated over their entire range to about double the intended maximum test pressure. However, in no case shall the range be less than __.

Gauge pressure, its calculation based on fluid dynamics principles like Bernoulli's equation, and its importance in various applications are crucial concepts in physics.

Explanation:

Gauge pressure refers to the pressure difference between two points, often measured relative to atmospheric pressure. When calculating gauge pressure, it is important to consider the height differential and any other relevant factors.

For instance, in a scenario where water emerges from a pipe due to a pressure difference created by elevation and diameter change, the gauge pressure can be determined using the principles of fluid dynamics and Bernoulli's equation to find the minimum required pressure for the water to exit at a certain speed.

Understanding gauge pressure is crucial in various applications, from hydraulic systems to plumbing and pressure vessel testing, ensuring the safe and efficient operation of fluid-based systems.