Certified Hyperbaric Technologist Practice Test

If the pressure increases to double the original pressure, what happens to the lung volume of a diver?

1. Increases by the same factor

2. Decreases to half

3. Remains constant

4. Increases to twice the volume

The correct answer is: Decreases to half

When a diver experiences an increase in pressure to double the original pressure, the lung volume decreases to half. This phenomenon can be explained by Boyle's Law, which states that for a given mass of gas at constant temperature, the volume of the gas is inversely proportional to the pressure. As the pressure increases, the gas molecules are compressed into a smaller volume. Therefore, if the pressure doubles, the lung volume will reduce to half of its original volume, provided the gas temperature remains constant. This principle is crucial for divers to understand, as it affects not only their breathing but also the potential risks they face, such as barotrauma, if they do not manage pressure changes appropriately. The other outcomes presented do not align with the physical properties of gases under pressure changes as described by Boyle's Law.