Gauge vs Absolute Pressure — Converting a Vessel Reading A pressure gauge on a vessel reads 25 bar (gauge). If atmospheric pressure is 1.03 bar, determine the absolute pressure inside the vessel. Take g = 9.81 m/s^2 (not directly needed).

Introduction / Context:Pressure instruments often indicate gauge pressure, which excludes atmospheric pressure. Many thermodynamic relations, however, require absolute pressure. Correctly converting between the two is a basic, critical skill.

Given Data / Assumptions:

• Gauge pressure p_g = 25 bar.
• Atmospheric pressure p_atm = 1.03 bar.
• Absolute pressure p_abs = p_g + p_atm for a standard gauge referenced to atmosphere.

Concept / Approach:By definition, p_abs = p_g + p_atm. Negative gauge readings would imply vacuum; here the gauge is positive, so we add p_atm to obtain the absolute pressure.

Step-by-Step Solution:Write p_abs = p_g + p_atm.Substitute values: p_abs = 25 + 1.03.Compute: p_abs = 26.03 bar.

Verification / Alternative check:As a quick check, absolute pressure must exceed gauge pressure by about 1 bar near sea level; 26.03 bar is reasonable.

Why Other Options Are Wrong:23.97 bar would be gauge minus atmosphere (vacuum case); 25 bar is gauge, not absolute; 34.81 bar has no basis in the given data.

Common Pitfalls:Confusing absolute and gauge references; mixing different units (Pa, kPa, bar) without consistent conversion.

Final Answer:26.03 bar