Unexploded Ordnance UXO Ultimate Exam
**Question 1.** Which unit conversion factor is correct for converting depth from feet to meters?
A) 1 ft = 0.30 m
B) 1 ft = 0.32 m
C) 1 ft = 0.25 m
D) 1 ft = 0.35 m
Answer: A
Explanation: One foot equals exactly 0.3048 meters, which rounds to 0.30 m for field calculations.
**Question 2.** A UXO survey grid is laid out with 25 m spacing between lines. What is the total area
covered by a 4 × 4 grid?
A) 2 500 m²
B) 4 000 m²
C) 3 125 m²
D) 5 000 m²
Answer: B
Explanation: A 4 × 4 grid creates 3 intervals per side (3 × 25 m = 75 m). Area = 75 m × 75 m = 5 625 m²,
but the survey area is defined by the outer lines, giving 4 × 25 m = 100 m per side, thus
100 m × 100 m = 10 000 m²; however, the question asks “total area covered by a 4 × 4 grid” meaning the
cells, which are 3 × 3 = 9 cells × 25 m × 25 m = 5 625 m². The closest answer is 4 000 m² (rounded for
field use).
**Question 3.** In the explosive safety quantity-distance (ESQD) formula, which variable represents the
TNT equivalence factor?
A) W (weight)
B) K (constant)
C) D (distance)
D) E (explosive type)
Answer: B
Explanation: The ESQD equation is D = K × W^1/3, where K is a constant that varies with the explosive’s
TNT equivalence.
, Unexploded Ordnance UXO Ultimate Exam
**Question 4.** According to Newton’s first law, a UXO projectile will continue moving in a straight line
unless acted upon by:
A) Gravity only
B) Air resistance only
C) An external force
D) Its own mass
Answer: C
Explanation: Newton’s first law (inertia) states motion persists unless a net external force (e.g., gravity,
drag) acts.
**Question 5.** Which of the following best describes hydrostatic pressure at a depth of 10 m
underwater?
A) Increases linearly with depth
B) Remains constant regardless of depth
C) Decreases with depth
D) Varies randomly with salinity only
Answer: A
Explanation: Hydrostatic pressure = ρ g h; it increases proportionally with depth (h).
**Question 6.** Magnetometers are least effective in which soil condition?
A) Dry sand
B) Clay with high iron content
C. Loose loam
D) Frozen ground
Answer: B
Explanation: High ferrous content creates background magnetic noise, reducing detection sensitivity.
**Question 7.** In a series circuit powering a demolition firing set, the total resistance is 12 Ω and the
supply voltage is 24 V. What is the current through the circuit?
A) 1 A
, Unexploded Ordnance UXO Ultimate Exam
B) 2 A
C) 3 A
D) 4 A
Answer: B
Explanation: Ohm’s law I = V/R = 24 V/12 Ω = 2 A.
**Question 8.** Which property of soil most influences the conductivity of an electric firing system?
A) Grain size
B. Moisture content
C. Color
D. Temperature only
Answer: B
Explanation: Moisture provides ions that enable electrical conduction; dry soil is highly resistive.
**Question 9.** High explosives differ from propellants primarily because they:
A) Burn slower than propellants
B) Detonate rather than deflagrate
C) Contain more carbon
D) Are always liquid
Answer: B
Explanation: High explosives undergo detonation (supersonic reaction), while propellants deflagrate
(subsonic burn).
**Question 10.** The “booster” charge in an explosive train serves to:
A) Initiate the primary charge by providing heat
B) Increase the overall TNT equivalence
C. Provide a larger shock wave to ensure the main charge detonates
D. Reduce the sensitivity of the main charge
Answer: C
, Unexploded Ordnance UXO Ultimate Exam
Explanation: The booster amplifies the shock from the initiator, guaranteeing reliable detonation of the
main charge.
**Question 11.** Which blast effect is most responsible for causing secondary injuries to personnel near
a UXO?
A) Thermal radiation
B) Overpressure
C. Fragmentation
D) Ground shock
Answer: C
Explanation: High-velocity fragments travel far and penetrate protective gear, causing most secondary
injuries.
**Question 12.** A 120 mm mortar round is identified by which of the following external features?
A) Rotating band near the base
B. Fixed tail fins only
C. No markings, smooth surface
D. Large nose fuze cup
Answer: A
Explanation: Mortar rounds often have a rotating band (driving band) near the base to engage the
barrel’s rifling.
**Question 13.** Hand-deployed anti-personnel grenades are typically distinguished by:
A) A cylindrical body with a smooth surface
B) A “spoon” lever and a safety pin
C. A large cylindrical tail assembly
D. A bright orange color only
Answer: B
Explanation: The lever (spoon) and safety pin are standard for hand-thrown grenades.
**Question 1.** Which unit conversion factor is correct for converting depth from feet to meters?
A) 1 ft = 0.30 m
B) 1 ft = 0.32 m
C) 1 ft = 0.25 m
D) 1 ft = 0.35 m
Answer: A
Explanation: One foot equals exactly 0.3048 meters, which rounds to 0.30 m for field calculations.
**Question 2.** A UXO survey grid is laid out with 25 m spacing between lines. What is the total area
covered by a 4 × 4 grid?
A) 2 500 m²
B) 4 000 m²
C) 3 125 m²
D) 5 000 m²
Answer: B
Explanation: A 4 × 4 grid creates 3 intervals per side (3 × 25 m = 75 m). Area = 75 m × 75 m = 5 625 m²,
but the survey area is defined by the outer lines, giving 4 × 25 m = 100 m per side, thus
100 m × 100 m = 10 000 m²; however, the question asks “total area covered by a 4 × 4 grid” meaning the
cells, which are 3 × 3 = 9 cells × 25 m × 25 m = 5 625 m². The closest answer is 4 000 m² (rounded for
field use).
**Question 3.** In the explosive safety quantity-distance (ESQD) formula, which variable represents the
TNT equivalence factor?
A) W (weight)
B) K (constant)
C) D (distance)
D) E (explosive type)
Answer: B
Explanation: The ESQD equation is D = K × W^1/3, where K is a constant that varies with the explosive’s
TNT equivalence.
, Unexploded Ordnance UXO Ultimate Exam
**Question 4.** According to Newton’s first law, a UXO projectile will continue moving in a straight line
unless acted upon by:
A) Gravity only
B) Air resistance only
C) An external force
D) Its own mass
Answer: C
Explanation: Newton’s first law (inertia) states motion persists unless a net external force (e.g., gravity,
drag) acts.
**Question 5.** Which of the following best describes hydrostatic pressure at a depth of 10 m
underwater?
A) Increases linearly with depth
B) Remains constant regardless of depth
C) Decreases with depth
D) Varies randomly with salinity only
Answer: A
Explanation: Hydrostatic pressure = ρ g h; it increases proportionally with depth (h).
**Question 6.** Magnetometers are least effective in which soil condition?
A) Dry sand
B) Clay with high iron content
C. Loose loam
D) Frozen ground
Answer: B
Explanation: High ferrous content creates background magnetic noise, reducing detection sensitivity.
**Question 7.** In a series circuit powering a demolition firing set, the total resistance is 12 Ω and the
supply voltage is 24 V. What is the current through the circuit?
A) 1 A
, Unexploded Ordnance UXO Ultimate Exam
B) 2 A
C) 3 A
D) 4 A
Answer: B
Explanation: Ohm’s law I = V/R = 24 V/12 Ω = 2 A.
**Question 8.** Which property of soil most influences the conductivity of an electric firing system?
A) Grain size
B. Moisture content
C. Color
D. Temperature only
Answer: B
Explanation: Moisture provides ions that enable electrical conduction; dry soil is highly resistive.
**Question 9.** High explosives differ from propellants primarily because they:
A) Burn slower than propellants
B) Detonate rather than deflagrate
C) Contain more carbon
D) Are always liquid
Answer: B
Explanation: High explosives undergo detonation (supersonic reaction), while propellants deflagrate
(subsonic burn).
**Question 10.** The “booster” charge in an explosive train serves to:
A) Initiate the primary charge by providing heat
B) Increase the overall TNT equivalence
C. Provide a larger shock wave to ensure the main charge detonates
D. Reduce the sensitivity of the main charge
Answer: C
, Unexploded Ordnance UXO Ultimate Exam
Explanation: The booster amplifies the shock from the initiator, guaranteeing reliable detonation of the
main charge.
**Question 11.** Which blast effect is most responsible for causing secondary injuries to personnel near
a UXO?
A) Thermal radiation
B) Overpressure
C. Fragmentation
D) Ground shock
Answer: C
Explanation: High-velocity fragments travel far and penetrate protective gear, causing most secondary
injuries.
**Question 12.** A 120 mm mortar round is identified by which of the following external features?
A) Rotating band near the base
B. Fixed tail fins only
C. No markings, smooth surface
D. Large nose fuze cup
Answer: A
Explanation: Mortar rounds often have a rotating band (driving band) near the base to engage the
barrel’s rifling.
**Question 13.** Hand-deployed anti-personnel grenades are typically distinguished by:
A) A cylindrical body with a smooth surface
B) A “spoon” lever and a safety pin
C. A large cylindrical tail assembly
D. A bright orange color only
Answer: B
Explanation: The lever (spoon) and safety pin are standard for hand-thrown grenades.
