Arizona Plumbing Practice Exam 2026 – Complete Preparation Guide

To determine the pressure exerted at the bottom of a water column, we can use the formula that relates the height of the water column to pressure. The pressure at the bottom of a column of water is given by the equation:

Pressure (psi) = Height (inches) x 0.433

Here, the height of the water column is 12 inches. By substituting this value into the formula:

Pressure = 12 inches x 0.433 psi/inch = 5.196 psi

However, in the context of the question, the conversion factor often used considers that 1 foot of water exerts approximately 0.433 psi. Since 12 inches equals 1 foot, applying this conversion correctly leads to a final calculation of 0.433 psi at the bottom of the 12-inch water column. This value is critical as it illustrates how hydrostatic pressure increases with the height of the liquid above a reference point. Understanding this concept is essential in plumbing and fluid mechanics, as it lays the groundwork for calculating pressures in various systems. Therefore, the correct choice is indeed the one that indicates 0.433 psi.