PADI Open Water Diver Final Examination |250 Multiple
Choice Questions with Answers & Rationales | latest
update | instant download
SECTION 1: Diving Physics and Physiology (Questions 1-50)
**1. As you descend in water, the pressure:**
- A. Decreases
- B. Remains the same
- C. Increases
- D. Fluctuates randomly
**Correct Answer: C. Increases**
*Rationale: Water pressure increases with depth due to the weight of the water above. Every 10
meters/33 feet of seawater adds one atmosphere of pressure . This is a fundamental concept all
divers must understand for safe diving practices.*
---
**2. A depth change of 10 meters/33 feet in seawater causes a pressure change of:**
- A. 1 bar/ata
- B. 2 bar/ata
- C. 3 bar/ata
- D. 4 bar/ata
**Correct Answer: A. 1 bar/ata**
,*Rationale: In seawater, each 10 meters/33 feet of depth equals one atmosphere of pressure.
The atmospheric pressure at the surface is 1 bar/ata, so at 10 meters the total pressure is 2
bar/ata .*
---
**3. If you take 6 liters of air from the surface to 20 meters/66 feet, the volume will be:**
- A. 6 liters
- B. 4 liters
- C. 3 liters
- D. 2 liters
**Correct Answer: D. 2 liters**
*Rationale: According to Boyle's Law, pressure and volume are inversely proportional. At 20
meters (3 bar total pressure), the volume decreases to one-third of its original volume (6 ÷ 3 = 2
liters) .*
---
**4. The density of air at 20 meters/66 feet would be _______ the density at the surface:**
- A. The same as
- B. Two times
- C. Three times
- D. Four times
,**Correct Answer: C. Three times**
*Rationale: As pressure increases, density increases proportionally. At 20 meters (3 bar total
pressure), air density is three times greater than at the surface .*
---
**5. A balloon fully inflated and sealed at 10 meters/33 feet would probably ________ during
ascent to the surface:**
- A. Shrink
- B. Remain the same size
- C. Expand or burst
- D. Collapse
**Correct Answer: C. Expand or burst**
*Rationale: As pressure decreases during ascent, trapped air volume expands according to
Boyle's Law. A sealed balloon will expand and may burst if the expanding air exceeds the elastic
limits of the balloon material .*
---
**6. As I descend, increasing pressure affects my:**
- A. Mask, ears, and sinuses
- B. Only my ears
- C. Only my mask
- D. Only my lungs
, **Correct Answer: A. Mask, ears, and sinuses**
*Rationale: All air spaces in the body are affected by increasing pressure during descent. The
mask, ears, and sinuses are the primary air spaces that require equalization during descent .*
---
**7. A squeeze is caused by:**
- A. Too much air in an air space
- B. A pressure imbalance between surrounding pressure and an air space
- C. Cold water
- D. Holding your breath
**Correct Answer: B. A pressure imbalance between surrounding pressure and an air space**
*Rationale: A squeeze occurs when the pressure outside an air space is greater than the
pressure inside, causing tissue damage. Proper equalization prevents this imbalance .*
---
**8. Equalization is the process of:**
- A. Removing air from an air space
- B. Adding air to an air space
- C. Holding air in an air space
- D. Ignoring pressure changes
Choice Questions with Answers & Rationales | latest
update | instant download
SECTION 1: Diving Physics and Physiology (Questions 1-50)
**1. As you descend in water, the pressure:**
- A. Decreases
- B. Remains the same
- C. Increases
- D. Fluctuates randomly
**Correct Answer: C. Increases**
*Rationale: Water pressure increases with depth due to the weight of the water above. Every 10
meters/33 feet of seawater adds one atmosphere of pressure . This is a fundamental concept all
divers must understand for safe diving practices.*
---
**2. A depth change of 10 meters/33 feet in seawater causes a pressure change of:**
- A. 1 bar/ata
- B. 2 bar/ata
- C. 3 bar/ata
- D. 4 bar/ata
**Correct Answer: A. 1 bar/ata**
,*Rationale: In seawater, each 10 meters/33 feet of depth equals one atmosphere of pressure.
The atmospheric pressure at the surface is 1 bar/ata, so at 10 meters the total pressure is 2
bar/ata .*
---
**3. If you take 6 liters of air from the surface to 20 meters/66 feet, the volume will be:**
- A. 6 liters
- B. 4 liters
- C. 3 liters
- D. 2 liters
**Correct Answer: D. 2 liters**
*Rationale: According to Boyle's Law, pressure and volume are inversely proportional. At 20
meters (3 bar total pressure), the volume decreases to one-third of its original volume (6 ÷ 3 = 2
liters) .*
---
**4. The density of air at 20 meters/66 feet would be _______ the density at the surface:**
- A. The same as
- B. Two times
- C. Three times
- D. Four times
,**Correct Answer: C. Three times**
*Rationale: As pressure increases, density increases proportionally. At 20 meters (3 bar total
pressure), air density is three times greater than at the surface .*
---
**5. A balloon fully inflated and sealed at 10 meters/33 feet would probably ________ during
ascent to the surface:**
- A. Shrink
- B. Remain the same size
- C. Expand or burst
- D. Collapse
**Correct Answer: C. Expand or burst**
*Rationale: As pressure decreases during ascent, trapped air volume expands according to
Boyle's Law. A sealed balloon will expand and may burst if the expanding air exceeds the elastic
limits of the balloon material .*
---
**6. As I descend, increasing pressure affects my:**
- A. Mask, ears, and sinuses
- B. Only my ears
- C. Only my mask
- D. Only my lungs
, **Correct Answer: A. Mask, ears, and sinuses**
*Rationale: All air spaces in the body are affected by increasing pressure during descent. The
mask, ears, and sinuses are the primary air spaces that require equalization during descent .*
---
**7. A squeeze is caused by:**
- A. Too much air in an air space
- B. A pressure imbalance between surrounding pressure and an air space
- C. Cold water
- D. Holding your breath
**Correct Answer: B. A pressure imbalance between surrounding pressure and an air space**
*Rationale: A squeeze occurs when the pressure outside an air space is greater than the
pressure inside, causing tissue damage. Proper equalization prevents this imbalance .*
---
**8. Equalization is the process of:**
- A. Removing air from an air space
- B. Adding air to an air space
- C. Holding air in an air space
- D. Ignoring pressure changes
