What term refers to the difference in pressure between two points?

• A. Atmospheric Pressure
• B. Gauge Pressure
• C. Absolute Pressure
• D. Pressure Differential

Answer: (D)

The idea here is the comparison between two pressures. When you talk about how much one pressure differs from another at a different point, that difference is called the pressure differential. It’s the amount by which one point’s pressure exceeds or falls short of another, and it’s exactly what many instruments and systems rely on to drive flow or indicate conditions.

Atmospheric pressure is the air pressure exerted by the atmosphere at a location, and absolute pressure is the total pressure relative to a perfect vacuum. Gauge pressure is the pressure above atmospheric pressure at a single point. Both gauge and absolute pressures are about a single location in relation to a reference (air or vacuum), but the scenario described—how much two points differ—uses the term pressure differential to express that two-point difference.