Certified Hyperbaric Technologist Practice Test

What chamber pressure is required to reduce the diameter of a gas bubble by half, starting from 1 ATA?

1. 1 ATA

2. 3 ATA

3. 6 ATA

4. 9 ATA

The correct answer is: 6 ATA

To understand the relationship between pressure and the volume of a gas bubble, we can apply Boyle’s Law, which states that for a given mass of gas at constant temperature, the pressure and volume of the gas are inversely proportional. Starting from a baseline pressure of 1 ATA (atmospheric pressure), if we want to reduce the diameter of a gas bubble by half, we need to consider how changes in pressure affect the volume of a gas. The diameter of the bubble is related to its volume; specifically, if the volume of a bubble is reduced, the diameter will proportionally reduce as well. To reduce the diameter by half, we need to reduce the volume of the bubble to one-eighth of its original volume, because volume is proportional to the cube of the diameter. According to Boyle’s Law, if the volume of the gas decreases, then the pressure must increase correspondingly. If we start with a gas bubble at 1 ATA, to find the pressure required to reduce the volume to one-eighth, we can set up the equation: \( P_1 \times V_1 = P_2 \times V_2 \) Here, \( P_1 \) is the initial pressure (1 ATA), and