Question 32General Subjects - QMED

The correct answer is C) The air pressure required to force air bubbles into the liquid near the bottom of the tank is proportional to the liquid level in the tank. This is because the operating principle of a bubble tube system is based on the hydrostatic pressure exerted by the liquid in the tank. The deeper the air bubbles are introduced into the liquid, the greater the pressure required to force the air through the liquid. As the liquid level increases, the hydrostatic pressure at the bottom of the tank also increases, requiring a higher air pressure to push the air bubbles through the liquid. This proportional relationship between the air pressure and the liquid level is the fundamental operating principle of a bubble tube level indicating system. The other options are incorrect because they do not accurately describe the relationship between the air pressure and the liquid level in a bubble tube system.