LP-GAS TEXAS BOBTAIL EXAM 250 UNIQUE
MULTIPLE-CHOICE QUESTIONS AND
ANSWERS WITH DETAILED RATIONALES
LATEST UPDATE 2026
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SECTION 1: GENERAL KNOWLEDGE & DEFINITIONS (Questions 1-30)
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Question 1
At what temperature does propane boil at atmospheric pressure?
A) 0°F
B) 32°F
C) -44°F
D) -20°F
Correct Answer: C) -44°F
Rationale: Propane boils at -44°F at atmospheric pressure. This is a critical
property because it explains why propane is stored and handled under pressure as a
liquid. Understanding this property is essential for recognizing that liquid propane
poses a severe cold burn hazard if released and that it will rapidly vaporize at
normal temperatures.
,---
Question 2
What is the lower limit of combustibility of odorized LP-gas?
A) 1/10
B) 1/5
C) 1/3
D) 1/2
Correct Answer: B) 1/5
Rationale: The lower limit of combustibility of odorized LP-gas is 1/5【11†L23-
L24】. This means that when the concentration of LP-gas in air reaches
approximately 2.1% (the 1/5 ratio), it becomes combustible. This knowledge is
essential for recognizing hazardous conditions and maintaining safe operating
environments.
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Question 3
The Bobtail examination qualifies an individual to operate a bobtail and perform
all LP-gas activities authorized by which other certifications?
A) Transport Driver, DOT Cylinder Filling, and Motor/Mobile Fuel
B) Service and Installation only
C) Recreational Vehicle Technician only
D) Management-Level Category C only
,Correct Answer: A) Transport Driver, DOT Cylinder Filling, and Motor/Mobile
Fuel
Rationale: The Bobtail examination authorizes an individual to operate a bobtail
and perform all LP-gas activities authorized by the Transport Driver, DOT
Cylinder Filling, and Motor/Mobile Fuel examinations. This includes performing
leak checks and pressure tests, lighting appliances, and adjusting regulators and
thermocouples.
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Question 4
What is the maximum time limit for the Bobtail employee-level examination?
A) 1 hour
B) 2 hours
C) 3 hours
D) 4 hours
Correct Answer: C) 3 hours
Rationale: The Bobtail employee-level examination is an open-book examination
limited to three hours. The examination proctor serves as the official timekeeper,
and examinees must submit their examination and answer sheet before or at the
end of the established time limit.
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Question 5
, The Bobtail examination does NOT authorize an individual to perform which
activity?
A) Operate a bobtail
B) Perform leak checks and pressure tests
C) Connect or disconnect containers
D) Light appliances
Correct Answer: C) Connect or disconnect containers
Rationale: The Bobtail examination does not authorize an individual to connect or
disconnect containers, except when performing a pressure test or removing a
container from service. This limitation is important because connecting and
disconnecting containers involves specific safety risks that require additional
training and certification.
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Question 6
What is a "bobtail" in the context of LP-gas operations?
A) A tractor without a semi-trailer
B) A truck equipped with an LP-gas cargo tank for delivery
C) A storage container at a bulk plant
D) A type of pressure regulator
Correct Answer: B) A truck equipped with an LP-gas cargo tank for delivery
MULTIPLE-CHOICE QUESTIONS AND
ANSWERS WITH DETAILED RATIONALES
LATEST UPDATE 2026
---
SECTION 1: GENERAL KNOWLEDGE & DEFINITIONS (Questions 1-30)
---
Question 1
At what temperature does propane boil at atmospheric pressure?
A) 0°F
B) 32°F
C) -44°F
D) -20°F
Correct Answer: C) -44°F
Rationale: Propane boils at -44°F at atmospheric pressure. This is a critical
property because it explains why propane is stored and handled under pressure as a
liquid. Understanding this property is essential for recognizing that liquid propane
poses a severe cold burn hazard if released and that it will rapidly vaporize at
normal temperatures.
,---
Question 2
What is the lower limit of combustibility of odorized LP-gas?
A) 1/10
B) 1/5
C) 1/3
D) 1/2
Correct Answer: B) 1/5
Rationale: The lower limit of combustibility of odorized LP-gas is 1/5【11†L23-
L24】. This means that when the concentration of LP-gas in air reaches
approximately 2.1% (the 1/5 ratio), it becomes combustible. This knowledge is
essential for recognizing hazardous conditions and maintaining safe operating
environments.
---
Question 3
The Bobtail examination qualifies an individual to operate a bobtail and perform
all LP-gas activities authorized by which other certifications?
A) Transport Driver, DOT Cylinder Filling, and Motor/Mobile Fuel
B) Service and Installation only
C) Recreational Vehicle Technician only
D) Management-Level Category C only
,Correct Answer: A) Transport Driver, DOT Cylinder Filling, and Motor/Mobile
Fuel
Rationale: The Bobtail examination authorizes an individual to operate a bobtail
and perform all LP-gas activities authorized by the Transport Driver, DOT
Cylinder Filling, and Motor/Mobile Fuel examinations. This includes performing
leak checks and pressure tests, lighting appliances, and adjusting regulators and
thermocouples.
---
Question 4
What is the maximum time limit for the Bobtail employee-level examination?
A) 1 hour
B) 2 hours
C) 3 hours
D) 4 hours
Correct Answer: C) 3 hours
Rationale: The Bobtail employee-level examination is an open-book examination
limited to three hours. The examination proctor serves as the official timekeeper,
and examinees must submit their examination and answer sheet before or at the
end of the established time limit.
---
Question 5
, The Bobtail examination does NOT authorize an individual to perform which
activity?
A) Operate a bobtail
B) Perform leak checks and pressure tests
C) Connect or disconnect containers
D) Light appliances
Correct Answer: C) Connect or disconnect containers
Rationale: The Bobtail examination does not authorize an individual to connect or
disconnect containers, except when performing a pressure test or removing a
container from service. This limitation is important because connecting and
disconnecting containers involves specific safety risks that require additional
training and certification.
---
Question 6
What is a "bobtail" in the context of LP-gas operations?
A) A tractor without a semi-trailer
B) A truck equipped with an LP-gas cargo tank for delivery
C) A storage container at a bulk plant
D) A type of pressure regulator
Correct Answer: B) A truck equipped with an LP-gas cargo tank for delivery
