Certified Hyperbaric Technologist Test Hyperbaric Physics Fundamentals 2 — Questions and Answers
Question 1: According to Boyle's Law, what happens to the volume of a fixed mass of gas as pressure increases at constant temperature?
- Volume increases proportionally
- Volume decreases inversely (Correct answer)
- Volume stays the same
- Volume doubles
Correct answer: Volume decreases inversely
Boyle's Law states that volume is inversely proportional to pressure at constant temperature.
Question 2: A gas bubble has a volume of 10 mL at the surface (1 ATA). What is its approximate volume at 2 ATA?
- 20 mL
- 10 mL
- 5 mL (Correct answer)
- 2.5 mL
Correct answer: 5 mL
By Boyle's Law, doubling absolute pressure halves the volume, so 10 mL becomes 5 mL.
Question 3: At what depth of seawater does the absolute pressure equal 2 ATA?
- 10 feet
- 33 feet (Correct answer)
- 66 feet
- 99 feet
Correct answer: 33 feet
Each 33 feet of seawater adds 1 atmosphere, so 33 feet plus surface equals 2 ATA.
Question 4: Which gas law explains why a sealed flexible container expands during ascent (decompression)?
- Charles's Law
- Boyle's Law (Correct answer)
- Henry's Law
- Dalton's Law
Correct answer: Boyle's Law
Boyle's Law explains volume expansion as ambient pressure decreases during ascent.
Question 5: The term 'ATA' stands for which of the following?
- Absolute Temperature Adjustment
- Atmospheres Absolute (Correct answer)
- Air Tension Average
- Ambient Treatment Atmosphere
Correct answer: Atmospheres Absolute
ATA means Atmospheres Absolute, the total pressure including atmospheric pressure.
Question 6: What is the gauge pressure at 33 feet of seawater?
- 0 ATA
- 1 ATA (Correct answer)
- 2 ATA
- 3 ATA
Correct answer: 1 ATA
Gauge pressure excludes the 1 ATA surface pressure, so 33 feet reads 1 ATA gauge.
Question 7: Why must hollow rigid air spaces in equipment be vented during compression?
- To prevent freezing
- To equalize pressure and prevent implosion or damage (Correct answer)
- To increase oxygen content
- To reduce humidity
Correct answer: To equalize pressure and prevent implosion or damage
Rigid air spaces must equalize to avoid pressure-related implosion or barotrauma to equipment.
Certified Hyperbaric Technologist Test Hyperbaric Physics Fundamentals 2
According to Boyle's Law, what happens to the volume of a fixed mass of gas as pressure increases at constant temperature?