Which statement about altitude is true?

• A. Altitude describes the total pressure loss in a hose
• B. Altitude is the position of an object above or below sea level
• C. Altitude is the center line of the pump
• D. Altitude is the term used to describe pressure gain only

Answer: (B)

Altitude is the vertical distance of a point above or below sea level. It’s a position measure, not a description of pressure loss or gain in a hose, nor a feature of the pump’s centerline. In firefighting hydraulics, elevation can affect the pressure you must provide to push water to higher points, since pressure in a water column changes with height, but altitude itself is simply height above or below sea level.