PADI Divemaster Certification Practice Exam

What is the relationship between changes in absolute pressure and gas volume?

1. They are inversely proportional

2. They have no relation

3. They are the same

4. They are randomly related

The correct answer is: They are the same

The correct answer indicates that changes in absolute pressure and gas volume are related in a manner defined by Boyle's Law. According to this principle, at a constant temperature, the volume of a given mass of gas is inversely proportional to its absolute pressure. This means that as the pressure increases, the volume decreases, and vice versa. When the absolute pressure acting on a gas increases, the gas molecules are compressed into a smaller space, resulting in a decrease in volume. Conversely, if the pressure decreases, there is less force pressing down on the gas, allowing it to expand and thus increasing in volume. This relationship is essential for divers to understand, as it directly impacts buoyancy and the behavior of gases during ascents and descents underwater. Understanding this inverse relationship allows divers to predict and manage the changes in gas volume as they move through different layers of water, ensuring safer and more effective diving practices.