HYPERBARIC TECHNOLOGY EXAM REVIEW WITH
ACCURATE SOLUTIONS
1. Boyle’s Law states that:
A. Pressure and volume are inversely proportional at constant temperature
B. Pressure and temperature are directly proportional
C. Volume and temperature are inversely proportional
D. Gas absorption is proportional to pressure
Answer: A
Explanation: Boyle’s Law describes the inverse relationship between pressure and
volume at constant temperature. As a diver ascends, gas expands in bubbles, explaining
bubble growth near the surface. Formula: P₁V₁ = P₂V₂.
2. Dalton’s Law states that:
A. Total pressure equals the sum of partial pressures of each gas
B. Gas volume decreases with pressure
C. Gas absorption is proportional to temperature
D. Gas volume is inversely proportional to pressure
Answer: A
Explanation: Dalton’s Law explains that the total pressure of a gas mixture is the sum of
its component gases’ partial pressures. Formula: P_total = P₁ + P₂ + …
3. Gay-Lussac’s Law states that:
A. Gas pressure is directly proportional to absolute temperature at constant volume
B. Gas volume is inversely proportional to pressure
C. Gas absorption is proportional to depth
D. Gas volume is proportional to dissolved gas
Answer: A
Explanation: At constant volume, pressure increases as temperature rises. This is
important in pressurized chambers where temperature changes can affect gas pressure.
Formula: P₁/T₁ = P₂/T₂.
4. Henry’s Law explains that:
A. The amount of gas dissolved in a liquid is proportional to its partial pressure
B. Gas volume decreases as pressure increases
C. Gas pressure and temperature are directly proportional
D. Gas volume is proportional to temperature
Answer: A
Explanation: Henry’s Law governs gas absorption into tissues. The deeper a diver goes,
the more nitrogen dissolves, increasing decompression requirements. Formula: Dissolved
Gas = K × P_gas.
5. Charles’ Law states that:
A. Gas volume is directly proportional to absolute temperature at constant pressure
B. Pressure and volume are inversely proportional
C. Gas absorption is proportional to depth
, D. Total pressure equals the sum of partial pressures
Answer: A
Explanation: Charles’ Law describes how gas volume expands with temperature if
pressure is constant. This is relevant in chamber gas volume changes during temperature
fluctuations. Formula: V₁/T₁ = V₂/T₂.
6. Common CNS oxygen toxicity symptoms include:
A. Tunnel vision, tinnitus, twitching, nausea, irritability
B. Fever and rash
C. Shortness of breath only
D. Muscle cramps only
Answer: A
Explanation: CNS oxygen toxicity can cause visual changes, tinnitus, facial twitching,
nausea, irritability, anxiety, confusion, and dizziness. Immediate action involves reducing
ppO₂ exposure.
7. Nitrogen narcosis symptoms include:
A. Poor judgment, memory issues, euphoria, hallucinations
B. Fever and chills
C. Rash and itching
D. Cough and congestion
Answer: A
Explanation: Nitrogen narcosis impairs cognition and motor skills. Symptoms worsen
with depth, usually noticeable around 100 fsw, and can affect diver safety.
8. Gas absorption in tissues is described by:
A. Henry’s Law
B. Boyle’s Law
C. Dalton’s Law
D. Charles’ Law
Answer: A
Explanation: Henry’s Law states that the amount of gas absorbed is proportional to
partial pressure. Deeper dives lead to greater nitrogen uptake, requiring decompression
stops.
9. Type 1 DCS symptoms include:
A. Pain, marbling, swelling
B. Nausea and vomiting
C. Hallucinations
D. Tinnitus only
Answer: A
Explanation: Type 1 DCS primarily affects skin and joints. Pain, skin mottling, and
swelling are typical, usually non-life-threatening but require monitoring.
10. Examples of Type 2 DCI include:
A. Neurological, pulmonary, inner ear, cardiac
B. Marbling, swelling, joint pain
C. Euphoria only
D. Tinnitus, nausea
Answer: A
, Explanation: Type 2 DCI affects major organ systems and can be serious. Immediate
hyperbaric therapy is often required.
11. ppO₂ of Nitrox 40 at 70 fsw is:
A. 1.8 atm
B. 2.0 atm
C. 2.4 atm
D. 3.0 atm
Answer: C
Explanation: ppO₂ = FO₂ × (Depth/33 +1). For Nitrox 40 at 70 fsw: 0.40 × (70/33 +1) ≈
2.44 atm. This exceeds recommended limits for prolonged exposure.
12. To maintain 3.0 ppO₂ at 90 fsw, O₂ percentage should be:
A. 65%
B. 75%
C. 80%
D. 100%
Answer: B
Explanation: FO₂ = ppO₂ / (Depth/33 +1). FO₂ = 3 / (90/33 +1) ≈ 0.75 or 75%. This
keeps ppO₂ at safe therapeutic levels.
13. Depth for 2.0 ppO₂ while breathing 75% O₂ is:
A. 33 fsw
B. 30 fsw
C. 28 fsw
D. 36 fsw
Answer: C
Explanation: Depth = (ppO₂/FO₂ –1) × 33 = (2/0.75 –1) × 33 ≈ 28 fsw. Divers must
monitor ppO₂ to avoid CNS toxicity.
14. VENTID protocol for CNS O₂ toxicity requires:
A. Switch to air, wait until asymptomatic
B. Stay at depth and continue oxygen
C. Rapid ascent
D. Ignore symptoms
Answer: A
Explanation: VENTID ensures safety by switching to air at depth until symptoms resolve,
preventing further oxygen toxicity.
15. Factors increasing DCS risk include:
A. Depth, bottom time, ascent rate, dehydration
B. Water temperature only
C. Salinity
D. Wetsuit color
Answer: A
Explanation: Deeper, longer dives, rapid ascents, and dehydration increase nitrogen
absorption and DCS risk.
16. Pulmonary oxygen toxicity symptoms include:
A. Cough, chest pain, shortness of breath
B. Tunnel vision and twitching
C. Euphoria
ACCURATE SOLUTIONS
1. Boyle’s Law states that:
A. Pressure and volume are inversely proportional at constant temperature
B. Pressure and temperature are directly proportional
C. Volume and temperature are inversely proportional
D. Gas absorption is proportional to pressure
Answer: A
Explanation: Boyle’s Law describes the inverse relationship between pressure and
volume at constant temperature. As a diver ascends, gas expands in bubbles, explaining
bubble growth near the surface. Formula: P₁V₁ = P₂V₂.
2. Dalton’s Law states that:
A. Total pressure equals the sum of partial pressures of each gas
B. Gas volume decreases with pressure
C. Gas absorption is proportional to temperature
D. Gas volume is inversely proportional to pressure
Answer: A
Explanation: Dalton’s Law explains that the total pressure of a gas mixture is the sum of
its component gases’ partial pressures. Formula: P_total = P₁ + P₂ + …
3. Gay-Lussac’s Law states that:
A. Gas pressure is directly proportional to absolute temperature at constant volume
B. Gas volume is inversely proportional to pressure
C. Gas absorption is proportional to depth
D. Gas volume is proportional to dissolved gas
Answer: A
Explanation: At constant volume, pressure increases as temperature rises. This is
important in pressurized chambers where temperature changes can affect gas pressure.
Formula: P₁/T₁ = P₂/T₂.
4. Henry’s Law explains that:
A. The amount of gas dissolved in a liquid is proportional to its partial pressure
B. Gas volume decreases as pressure increases
C. Gas pressure and temperature are directly proportional
D. Gas volume is proportional to temperature
Answer: A
Explanation: Henry’s Law governs gas absorption into tissues. The deeper a diver goes,
the more nitrogen dissolves, increasing decompression requirements. Formula: Dissolved
Gas = K × P_gas.
5. Charles’ Law states that:
A. Gas volume is directly proportional to absolute temperature at constant pressure
B. Pressure and volume are inversely proportional
C. Gas absorption is proportional to depth
, D. Total pressure equals the sum of partial pressures
Answer: A
Explanation: Charles’ Law describes how gas volume expands with temperature if
pressure is constant. This is relevant in chamber gas volume changes during temperature
fluctuations. Formula: V₁/T₁ = V₂/T₂.
6. Common CNS oxygen toxicity symptoms include:
A. Tunnel vision, tinnitus, twitching, nausea, irritability
B. Fever and rash
C. Shortness of breath only
D. Muscle cramps only
Answer: A
Explanation: CNS oxygen toxicity can cause visual changes, tinnitus, facial twitching,
nausea, irritability, anxiety, confusion, and dizziness. Immediate action involves reducing
ppO₂ exposure.
7. Nitrogen narcosis symptoms include:
A. Poor judgment, memory issues, euphoria, hallucinations
B. Fever and chills
C. Rash and itching
D. Cough and congestion
Answer: A
Explanation: Nitrogen narcosis impairs cognition and motor skills. Symptoms worsen
with depth, usually noticeable around 100 fsw, and can affect diver safety.
8. Gas absorption in tissues is described by:
A. Henry’s Law
B. Boyle’s Law
C. Dalton’s Law
D. Charles’ Law
Answer: A
Explanation: Henry’s Law states that the amount of gas absorbed is proportional to
partial pressure. Deeper dives lead to greater nitrogen uptake, requiring decompression
stops.
9. Type 1 DCS symptoms include:
A. Pain, marbling, swelling
B. Nausea and vomiting
C. Hallucinations
D. Tinnitus only
Answer: A
Explanation: Type 1 DCS primarily affects skin and joints. Pain, skin mottling, and
swelling are typical, usually non-life-threatening but require monitoring.
10. Examples of Type 2 DCI include:
A. Neurological, pulmonary, inner ear, cardiac
B. Marbling, swelling, joint pain
C. Euphoria only
D. Tinnitus, nausea
Answer: A
, Explanation: Type 2 DCI affects major organ systems and can be serious. Immediate
hyperbaric therapy is often required.
11. ppO₂ of Nitrox 40 at 70 fsw is:
A. 1.8 atm
B. 2.0 atm
C. 2.4 atm
D. 3.0 atm
Answer: C
Explanation: ppO₂ = FO₂ × (Depth/33 +1). For Nitrox 40 at 70 fsw: 0.40 × (70/33 +1) ≈
2.44 atm. This exceeds recommended limits for prolonged exposure.
12. To maintain 3.0 ppO₂ at 90 fsw, O₂ percentage should be:
A. 65%
B. 75%
C. 80%
D. 100%
Answer: B
Explanation: FO₂ = ppO₂ / (Depth/33 +1). FO₂ = 3 / (90/33 +1) ≈ 0.75 or 75%. This
keeps ppO₂ at safe therapeutic levels.
13. Depth for 2.0 ppO₂ while breathing 75% O₂ is:
A. 33 fsw
B. 30 fsw
C. 28 fsw
D. 36 fsw
Answer: C
Explanation: Depth = (ppO₂/FO₂ –1) × 33 = (2/0.75 –1) × 33 ≈ 28 fsw. Divers must
monitor ppO₂ to avoid CNS toxicity.
14. VENTID protocol for CNS O₂ toxicity requires:
A. Switch to air, wait until asymptomatic
B. Stay at depth and continue oxygen
C. Rapid ascent
D. Ignore symptoms
Answer: A
Explanation: VENTID ensures safety by switching to air at depth until symptoms resolve,
preventing further oxygen toxicity.
15. Factors increasing DCS risk include:
A. Depth, bottom time, ascent rate, dehydration
B. Water temperature only
C. Salinity
D. Wetsuit color
Answer: A
Explanation: Deeper, longer dives, rapid ascents, and dehydration increase nitrogen
absorption and DCS risk.
16. Pulmonary oxygen toxicity symptoms include:
A. Cough, chest pain, shortness of breath
B. Tunnel vision and twitching
C. Euphoria
