Topic: Fluid Mechanics
A bourdon gauge connected to a closed tank indicates 40 kPa at a place where the atmospheric pressure is 95.48 kPa. If the tank is carried to a higher elevation where the atmospheric pressure is 90 kPa, the reading of the gauge will be
- A. 35 kPa
- B. 60.37 kPa
- C. 45.48 kPa
- D. 25.37 kPa
Answer: C. 45.48 kPa
Explanation: Absolute pressure inside the closed tank remains constant regardless of elevation.
$P_{abs} = P_{gauge1} + P_{atm1} = 40 + 95.48 = 135.48~kPa$.
At the new elevation, the new atmospheric pressure $P_{atm2} = 90~kPa$.
The new gauge reading $P_{gauge2} = P_{abs} - P_{atm2} = 135.48 - 90 = 45.48~kPa$.