Latest CFPS Actual Free Exam Updated 104 Questions [Q43-Q63]

Explanation
A proprietary fire alarm system is a type of fire alarm system that transmits signals that are permanently recorded at a constantly attended supervising station located either at the protected premises or at another location of the property owner. A proprietary fire alarm system is owned and operated by the property owner or the owner’s agent. A proprietary fire alarm system is intended to provide fire alarm service to a single property or a campus of related properties.References:
NFPA 72: National Fire Alarm and Signaling Code, 2019 Edition, Section 3.3.105.11 Fire Protection Handbook, 20th Edition, Volume 1, Chapter 7, Section 7.2.1.12

Explanation
Cellulose nitrate products begin to decompose at about 300 °F (150 °C). This is the temperature at which the nitrate ester bonds start to break down and release nitric acid, which further catalyzes the decomposition. The decomposition temperature depends on the nitrogen content, the stabilizers, and the external heating rate of the cellulose nitrate. Higher nitrogen content, lower stabilizer concentration, and faster heating rate lower the decomposition temperature and increase the risk of thermal runaway.
References:Nitrocellulose – Wikipedia;Comparative analysis of stable decomposition and combustion kinetics of nitrated cellulose;Degradation of aged nitrocellulose investigated by thermal analysis methods;Nitrocellulose;Effect of stabilizers and nitrogen content on thermal properties of nitrocellulose

Explanation
According to NFPA 230: Standard for the Fire Protection of Storage, 2015 Edition, building codes should limit the size of an unsprinklered facility used for the processing and storage of Municipal Solid Waste (MSW) built of type V construction to 7,500 ft2 (697 m2). This is based on the assumption that the MSW has a heat release rate of 18,000 Btu/ft2-min (200 kW/m2) and a fire growth rate of 0.046 min-1.Type V construction is defined as a type of construction in which the structural elements, exterior walls, and interior walls are of any materials permitted by the code123 References:
NFPA 230: Standard for the Fire Protection of Storage
5 Types of Construction per the IBC | Building Code Trainer
2.4 MUNICIPAL SOLID WASTE LANDFILLS – U.S. Environmental Protection Agency

Explanation

Standpipe
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175 psi (1207 kPa).
For standpipe systems containing 11/2 – 21/2 in. (40 – 65 mm) hose connection outlets without preconnected hose, a pressure regulating device is required when the pressure exceeds 175 psi (1207 kPa), according to NFPA 14, Standard for the Installation of Standpipe and Hose Systems, 2019 edition. This requirement applies to Class I and Class III standpipe systems, which are intended for use by fire department personnel or trained occupants. A pressure regulating device is a device that automatically reduces and controls the pressure of the water flowing through the hose connection outlet to a predetermined value.This device helps to prevent excessive pressure that could damage the hose, nozzle, or fittings, or cause difficulty in handling the hose stream123 References:
NFPA 14: Standard for the Installation of Standpipe and Hose Systems1
Standpipe System Design and Calculations | NFPA | NFPA2
ENGINE COMPANY STANDPIPE OPERATIONS:PRESSURE-REGULATING DEVICES3

Explanation
20 years.
According to NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, 2020 edition, fast response sprinklers are those that have a response time index (RTI) of 50 (m s)^(1/2) or less.These sprinklers are designed to activate faster than standard response sprinklers in the event of a fire, and they are typically used in light hazard, ordinary hazard, and residential occupancies1 NFPA 25 requires initial testing of representative samples of fast response sprinklers after 20 years from the date of manufacture, and subsequent testing every 10 years thereafter. The testing involves removing a minimum of four sprinklers or 1% of the total number of sprinklers per individual sprinkler sample, whichever is greater, and sending them to a recognized testing laboratory. The laboratory will perform a plunge test, which measures the time it takes for the sprinkler to operate when exposed to a specified air temperature.The test results will indicate whether the sprinklers meet the acceptance criteria or need to be replaced123 References:
NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems1 Sprinkler System Inspections, Testing, and Maintenance Frequencies Explained | NFPA4 Sprinkler Testing on Quick Response Sprinklers: What You Need to Know2 NFPA 25 ITM Quick Reference Guide – hillgrp.com3

Explanation
According to the Consumer Products Safety Commission (CPSC), the most common type of fabric used on upholstered furniture is cellulosic. Cellulosic fabrics are made from natural fibers derived from plants, such as cotton, linen, rayon, and hemp. Cellulosic fabrics account for about 51% of the total fabric weight used on upholstered furniture in the United States1. Cellulosic fabrics are popular because they are soft, comfortable, breathable, and versatile. However, they are also highly flammable and can contribute to the spread of fire if ignited2. Therefore, the CPSC has established a flammability standard for upholstered furniture that requires cellulosic fabrics to pass a smolder resistance test3. References:
Upholstered Furniture Business Education | CPSC.gov
Fire Fighting Foams – Chemguard
Standard for the Flammability of Residential Upholstered Furniture

Explanation
Two-dimensional models are not a common type of road tunnel fire models. Most road tunnel fire models are either one-dimensional, zone, or field models. One-dimensional models use a simplified approach to describe the fire and smoke behavior along the tunnel axis, assuming uniform conditions across the tunnel cross-section. Zone models divide the tunnel into two or more zones, each with uniform properties, and apply mass and energy conservation equations to each zone. Field models use computational fluid dynamics (CFD) to solve the governing equations for mass, momentum, energy, and species transport in a three-dimensional grid, capturing the spatial and temporal variations of the fire and smoke phenomena. Two-dimensional models are rarely used for road tunnel fire simulations, as they cannot account for the complex three-dimensional effects of fire and ventilation in tunnels.
References:Design Fires in Road Tunnels | The National Academies Press;CFD Modelling of Fire Ventilation in Road Tunnels – Academia.edu;Findings of the International Road Tunnel Fire Detection Research …1

Explanation
Fire alarm systems audible appliances ratings are usually stated as a sound pressure level (SPL) at 10 ft (3.05 m) from the appliance. The SPL is measured in decibels (dB) and indicates the loudness of the sound produced by the appliance. The SPL at 10 ft (3.05 m) is used as a standard reference point for comparing different audible appliances and for designing fire alarm systems to meet the required audibility levels.References:
NFPA 72: National Fire Alarm and Signaling Code, 2019 Edition, Section 18.4.3.11 Fire Protection Handbook, 20th Edition, Volume 1, Chapter 7, Section 7.8.2.12

Explanation
The safety class for propane refrigerant R-290 is A3, which means it has no toxicity but high flammability.
The safety class is determined by the ASHRAE Standard 34, which assigns a capital letter (A or B) for the toxicity level and a number (1, 2, or 3) for the flammability level of a refrigerant. Propane has a very low global warming potential and ozone depletion potential, but it also has a very low flash point and high auto ignition temperature, which make it highly flammable in the presence of ignition sources.References:Propane R-290 | Copeland US;R-290 Propane Refrigerant Fact & Info Sheet;Safety Data Sheet – Refrigerants; NFPA Fire Protection Handbook, 21st Edition, Chapter 3, Section 3.3.4.

Explanation
According to the web search results, titanium is the pure metal in its solid form in oxygen that has the highest ignition temperature in degrees Fahrenheit.The spontaneous-ignition temperature of titanium in the solid phase (below melting) is about 3020°F (1660°C)1.Aluminum, potassium, and zirconium have lower ignition temperatures in the solid phase, ranging from 1292°F (700°C) to 1652°F (900°C)23.References:
IGNITION OF METALS IN HIGH PRESSURE OXYGEN2
Combustion of Metals in Oxygen-Enriched Atmospheres3
High-temperature oxidation and ignition of metals1

Explanation
The correct answer is B. In wide-open spaces, the sound pressure level (SPL) decreases by 6 decibels (dB) every time the distance from the source is doubled. This is known as the inverse square law of sound propagation, which states that the intensity of sound is inversely proportional to the square of the distance from the source.For example, if the SPL at 1 meter from the source is 100 dB, then the SPL at 2 meters from the source is 94 dB, and the SPL at 4 meters from the source is 88 dB123

Explanation

Fire extinguisher
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smothering.
The primary mechanism by which carbon dioxide extinguishes fire is smothering, or displacing the oxygen that the fire needs to sustain combustion. Carbon dioxide is a gas that is heavier than air, so when it is released from the extinguisher, it forms a blanket over the fire and pushes away the oxygen.Without oxygen, the fire cannot continue to burn and is extinguished1234 Cooling is a secondary mechanism by which carbon dioxide extinguishes fire. Carbon dioxide is stored as a liquid under high pressure in the extinguisher, and when it is released, it expands rapidly and cools down. The cold gas absorbs heat from the fire and lowers the temperature of the fuel below its ignition point.However, cooling is not the main effect of carbon dioxide, as it is less effective than water in reducing the heat of the fire1234 Saponification and chemical inhibition are not mechanisms by which carbon dioxide extinguishes fire.
Saponification is a process by which wet chemical agents react with fats and oils to form a soapy foam that seals the surface of the fire and prevents re-ignition. Chemical inhibition is a process by which dry chemical agents interfere with the chemical chain reaction of the fire and stop the production of free radicals that propagate the combustion.These mechanisms are used by other types of fire extinguishers, such as Class K and Class D extinguishers, respectively1234 References:
Carbon Dioxide Extinguishers – University of South Carolina4
How Does A Co2 Fire Extinguisher Work2
Why is Carbon Dioxide Used to Extinguish Oil Fires3
What is a Carbon Dioxide Fire Extinguisher?- Safeopedia1

Explanation
According to NFPA 70: National Electrical Code (NEC) 2020 Edition, Article 230.71(A), each service shall have only one disconnecting means unless the requirements of 230.71(B) are met, which provide four specific service configurations. In each configuration, there shall be not more than six switches or sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, per service grouped in any one location. Therefore, the maximum number of additional switches or circuit breakers allowed for a separate service is six.References:
NFPA 70: National Electrical Code (NEC) 2020 Edition, Article 230.71(A) and (B)12 ElectricalLicenseRenewal.com, 230.71 Maximum Number of Disconnects3

Explanation
Aqueous film-forming agents (AFFF) are synthetic foam concentrates that can be proportioned into final concentrations of 1%, 3%, and 6%, depending on the type of fuel and application method12. AFFF forms a thin aqueous film on the surface of the flammable liquid, which prevents vapor release and provides rapid fire knockdown and extinguishment3. AFFF is suitable for Class B fires involving hydrocarbon fuels such as gasoline, diesel, kerosene, etc. References:
Fire Fighting Foams – Chemguard
Extinguishing foam: types, operation and application areas
[NFPA 11: Standard for Low-, Medium-, and High-Expansion Foam]

Explanation
Governor
For engine driven emergency power supplies, the device that maintains a relatively constant speed of the prime mover throughout the full power output range by varying the fuel input to the prime mover is the governor. A governor is a device that automatically regulates the speed or power of an engine or other prime mover by adjusting the amount of fuel supplied to it. A governor senses the speed of the prime mover and compares it with a desired set point, and then controls the fuel valve to increase or decrease the fuel flow accordingly.By doing so, the governor ensures that the prime mover operates within a narrow range of speed or power, regardless of the load or other factors that may affect its performance12

Explanation

Fire pump
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Typical fire pump drivers reach maximum brake horsepower (BHP) between 140% and 170% of rated capacity, depending on the type and size of the pump. This means that the driver must be able to provide enough power to operate the pump at its peak efficiency point, which is usually beyond the rated capacity. The rated capacity is the flow rate at which the pump is designed to deliver a certain pressure, as specified by NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection. The maximum BHP is the highest power output required by the pump at any point on its performancecurve. The driver must be sized to match the maximum BHP of the pump, with some allowance for service factor and safety margin.References
:Understanding the Basics of Fire Pumps | Pumps & Systems;How are Engines and Motors Sized for Fire Pumps?; NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, 2023 Edition, Chapter 4, Section 4.7.

Explanation
The correct answer is B. After an emergency incident has occurred, a post-incident critique of the emergency preparedness procedure should be conducted covering the detection of the incident, implementation of incident command, andnotification, alerting and warning procedures. These are some of the key elements of an effective emergency response that need to be evaluated and improved after an incident.A post-incident critique is a systematic review of the actions and decisions taken during an emergency incident, with the aim of identifying lessons learned, best practices, gaps, and corrective actions1.A post-incident critique should involve all the relevant stakeholders, such as emergency responders, emergency managers, facility managers, and affected community members2.A post-incident critique should also follow a structured format, such as the one suggested by the Federal Emergency Management Agency (FEMA)3:
Introduction: The facilitator introduces the purpose, objectives, ground rules, and agenda of the critique session.
Incident Overview: The facilitator provides a brief summary of the incident, including the date, time, location, type, size, and impact of the incident.
Timeline Review: The facilitator leads a chronological review of the major events and actions that occurred during the incident, using a timeline or a log as a reference.
Strengths and Areas for Improvement: The facilitator solicits feedback from the participants on what went well and what needs to be improved, focusing on the following topics:
Detection of the incident: How was the incident detected and reported? How timely and accurate was the information? How effective were the communication systems and protocols?
Implementation of incident command: How was the incident command system established and maintained? How clear and appropriate were the roles and responsibilities of the incident commander and other staff? How well did the incident command coordinate with other agencies and organizations?
Notification, alerting and warning procedures: How were the internal and external stakeholders notified, alerted, and warned about the incident? How timely and accurate were the messages?
How effective were the methods and channels of communication?
Other topics: Depending on the nature and scope of the incident, other topics may include resource management, operational tactics, safety and security, public information, recovery and restoration, etc.
Action Plan: The facilitator summarizes the main findings and recommendations from the critique session, and assigns responsibilities and deadlines for implementing the corrective actions.
Conclusion: The facilitator thanks the participants for their contributions, and provides information on how the results of the critique will be documented and shared.

Explanation
Fire alarm visible appliance source intensity is measured in candela, which is the unit of luminous intensity in a given direction. Candela is defined as the amount of light emitted by a single candle in a specific direction.
The intensity of a strobe light depends on the candela rating, the flash rate, and the flash duration. The higher the candela rating, the brighter the light. The National Fire Protection Association (NFPA) and the Americans with Disabilities Act (ADA) have established minimum and maximum candela ratings for fire alarm visible appliances in different locations and applications.References:Strobe Light Requirements: Proper location of visible notification …;Handbook of Visual Notification Appliances for Fire Alarm Applications;Audible Visible Appliance Reference Guide – Fire – studylib.net