Measurement of Pressure MCQs – Part 3
8 questions. Tap an option to check it instantly, then read the solution.
Answer: B. 2.52 m
Differential head h = x · (S_Hg/S_w − 1) = 0.20 · (13.6 − 1) = 0.20 × 12.6 = 2.52 m of water.
Answer: D. P_abs = P_atm + P_gauge
Absolute pressure is measured from complete vacuum: P_abs = P_atm + P_gauge.
Answer: D. Pressure
A manometer is a primary fluid instrument specifically designed for measuring fluid pressure.
Answer: B. Absolute pressure minus atmospheric pressure
Gauge pressure is defined as: Gauge pressure = Absolute pressure − Atmospheric pressure.
Answer: D. Absolute pressure at a point
The examination key designates (d) 'Absolute pressure at a point' (while distinguishing that differential U-tubes measure difference between two points, and simple open U-tubes measure gauge pressure at a point).
Answer: A. Large
Because mercury has an exceptionally high specific gravity (13.6), it produces compact, manageable column deflections when the pressure difference is large.
Answer: A. stagnation pressure
The Pitot tube senses stagnation pressure at its nose (with the book key designating stagnation pressure; a combined Pitot-static tube measures both stagnation and static to determine velocity).
Answer: A. milibar
1 millibar = 100 Pa, 1 mm Hg = 133.3 Pa, 1 kgf/cm² = 98,066 Pa, 1 N/mm² = 1,000,000 Pa. The smallest pressure unit is the millibar.