Question 1

What is the minimum pipe diameter size for direct discharge of steam inside a water tank?

Accepted Answer

D

Question 2

Fire alarm systems audible appliances ratings are usually stated as a sound pressure level (SPL) at what distance?

Accepted Answer

B

Explanation: The sound pressure level (SPL) rating for fire alarm audible appliances is standardized to ensure consistent and reliable system design. According to NFPA 72, Annex A, the sound output for these devices is measured in an anechoic chamber at a distance of 10 ft (3.05 m). This standardized rating provides a baseline for designers to calculate the effective sound level at various locations within a protected space, accounting for sound attenuation over distance and ambient noise levels. This allows for proper verification that the required sound levels, such as 15 dBA above average ambient sound level, are met throughout the occupiable area.

Question 3

What temperature measurement device consists of a pair of wires of different metals or alloys
welded together at a point to form a junction to compare the voltage magnitude compared with a
compensating junction at 0°C and the voltage difference calibrated to give the temperature in
degrees?

Accepted Answer

C

Explanation: A thermocouple is a temperature-sensing device that operates on the thermoelectric principle known as the Seebeck effect. It consists of two wires made from different, dissimilar metals joined at one end to form a measuring junction. When this junction is exposed to a temperature different from the other end (the reference junction), a small, predictable voltage is generated. This voltage is proportional to the temperature difference between the two junctions. By maintaining the reference junction at a known temperature (often electronically compensated), the measured voltage can be accurately calibrated to indicate the temperature at the measuring junction.

Question 4

Large quantities of flammable or combustible liquids (all classes) are best transferred

Accepted Answer

C

Explanation: Transferring large quantities of flammable or combustible liquids through a properly designed and engineered closed piping system using pumps is the safest, most reliable, and most common industrial method. This approach allows for precise control of flow rates and pressures, minimizes vapor emissions, and can be integrated with critical safety features like emergency shut-off valves and interlocks. NFPA 30, Flammable and Combustible Liquids Code, provides extensive requirements for such systems, establishing them as the standard for bulk transfer operations due to their inherent safety and control advantages over other methods.

Question 5

The coefficient of discharge of a fire hydrant when the outlet is smooth and well-rounded outlet is?

Accepted Answer

A

Explanation: The coefficient of discharge (Cd) is a dimensionless number used in the formula for calculating flow from a fire hydrant outlet. It accounts for the energy losses due to friction and the contraction of the water stream as it exits the orifice. For a hydrant outlet that is smooth and well-rounded, the flow is more efficient with minimal stream contraction, resulting in a higher coefficient. The standard value used in hydraulic calculations for this type of outlet is 0.90. This value is empirically derived and widely accepted in fire protection engineering for flow testing.

Question 6

What is the occupancy factor used by the Insurance Services Office (ISO) for computing required fire flow for C-3 (Combustible)?

Accepted Answer

B

Explanation: The Insurance Services Office (ISO) method for calculating Needed Fire Flow (NFF) uses an Occupancy Hazard Factor (Oi) to adjust the calculation based on the combustibility of the building's contents. The FSRS categorizes occupancies from C-1 (Noncombustible) to C-5 (Rapid-Burning). A C-3 (Combustible) classification represents occupancies with contents that burn with moderate rapidity, such as department stores, paper manufacturing, and woodworking shops. For this specific classification, the ISO Fire Suppression Rating Schedule (FSRS) assigns an occupancy factor of 0.85. This factor is multiplied by other variables in the NFF formula to determine the water supply required for firefighting operations.

Question 7

The minimum carbon dioxide design concentration for extinguishment of an ethylene fire is

Accepted Answer

C

Explanation: NFPA 12 lists required design concentrations of carbon dioxide for total-flooding extinguishment of specific fuels. In Table 5.5.2 (2021 ed.) ethylene (a flammable gas) requires a minimum CO₂ concentration of 43 % by volume. Concentrations lower than this do not reliably reduce the oxygen content of the atmosphere to the level needed to stop ethylene flame propagation; higher values are allowed but are not the “minimum design” value the standard specifies.

Question 8

At what temperature do cellulose nitrate products begin to decompose?

Accepted Answer

D

Explanation: Cellulose nitrate is a thermally unstable material that undergoes exothermic decomposition. While slow decomposition can begin at temperatures as low as 120°F (49°C), the rate accelerates significantly with increasing temperature. At approximately 300°F (149°C), the decomposition becomes very rapid, releasing large volumes of flammable and toxic gases (such as oxides of nitrogen, carbon monoxide, and carbon dioxide). This rapid decomposition can lead to spontaneous ignition and, under confinement, may become explosive. For fire protection purposes, 300°F (149°C) is considered the critical temperature at which the hazard becomes acute.

Question 9

Which smoke detector type contains a small amount of radioactive material and functions by sensing a decrease in conductance of the air when smoke particles enter the chamber?

Accepted Answer

D

Explanation: Ionization smoke detectors utilize a small amount of a radioactive isotope, typically Americium-241, to create a constant flow of ionized air particles between two electrodes within a sensing chamber. This flow establishes a small, measurable electrical current. When smoke particles from a fire enter the chamber, they attach to the ions, neutralizing them. This action disrupts the current flow, effectively decreasing the electrical conductance of the air. The detector's circuitry senses this drop in current and triggers the alarm. This technology is particularly sensitive to the small particles produced by fast-flaming fires.

Question 10

What type of property classifications experience the majority of fire deaths in the United States?

Accepted Answer

D

Explanation: Statistical data compiled by the National Fire Protection Association (NFPA) consistently demonstrates that the overwhelming majority of civilian fire deaths in the United States occur in residential properties. Among residential structures, one- and two-family dwellings account for the largest share of these fatalities. This is largely due to occupants being asleep and potentially delayed notification from smoke alarms, as compared to the more stringent fire protection systems, building codes, and occupant awareness typically found in non-residential properties. In 2022, fires in one- and two-family homes accounted for 74% of all civilian fire deaths.

Question 11

Wet chemical extinguishing agents when sprayed on a grease fire, extinguish the fire by

Accepted Answer

A

Explanation: Wet chemical extinguishing agents are specifically designed for Class K (cooking media) fires. When applied, the alkaline agent reacts with the hot cooking oil or fat in a chemical process called saponification. This reaction forms a thick, soapy foam blanket on the surface of the fuel. This blanket smothers the fire by separating the fuel from atmospheric oxygen. Concurrently, the water content of the agent evaporates, providing a significant cooling effect that lowers the temperature of the cooking medium below its autoignition point. This dual mechanism of smothering and cooling is essential for effective extinguishment and preventing re-ignition.

Question 12

What is the background color used from the source to the outlets of a nitrous oxide medical gas system?

Accepted Answer

C

Explanation: NFPA 99, Health Care Facilities Code, establishes mandatory identification standards for medical gas systems to prevent catastrophic errors. The standard requires that gas-specific color-coding be used on piping, outlets, and source equipment. For nitrous oxide (N₂O), the designated background color is blue. This color must be visible along the entire distribution system, from the central supply source to the final outlets in patient care areas, ensuring immediate and unambiguous identification of the gas. This system is critical for patient safety, particularly in anesthesia and respiratory care settings.

Question 13

Critical Radiant Flux is used to classify

Accepted Answer

C

Explanation: Critical Radiant Flux (CRF) is the measure of a material's tendency to support flame spread and is the primary output of the test method defined in NFPA 253, Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source. This test is specifically designed to evaluate the fire performance of interior floor finishes, such as carpets and resilient flooring, when exposed to a graded radiant heat flux in a corridor-like environment. Building and life safety codes, such as NFPA 101, use the CRF value (measured in W/cm²) to classify floor finishes into Class I or Class II, determining their suitability for use in different locations within a building, particularly in exit access corridors and other parts of the means of egress.

Question 14

What is the leading cause of home fires?

Accepted Answer

D

Explanation: According to the National Fire Protection Association (NFPA), cooking is the leading cause of reported home structure fires and home fire injuries. Unattended cooking is the primary factor contributing to these incidents. Annually, cooking activities account for nearly half of all residential fires, far surpassing other causes in frequency. While other sources like heating equipment are significant contributors to fire deaths, cooking remains the number one cause of the fires themselves.

Question 15

Which of the following would NOT be an appropriate purpose for employing a guard service to protect a property against fire loss?

Accepted Answer

C

Explanation: The primary function of a guard service in fire loss prevention is to provide surveillance, early detection, reporting, and initial response to fire-related emergencies. Assigning duties such as routine housekeeping or equipment maintenance is inappropriate as it diverts the guard's attention from their core security and fire watch responsibilities. While guards are expected to observe and report poor housekeeping or malfunctioning equipment as potential fire hazards during their patrols, they are not responsible for performing these corrective tasks themselves. Such duties fall under the responsibility of dedicated maintenance or custodial staff.

Free NFPA CFPS Actual Exam Questions