Question 6 of 99
Electrical equipment used in Class I, Division I hazardous locations is often referred to as:
Correct Answer: D

Electrical equipment used in Class I, Division I hazardous locations is often referred to as explosion proof. This type of equipment is designed to contain any explosion originating within its housing and prevent the ignition of the surrounding flammable atmosphere.

Question 7 of 99
The entrainment of air from the surrounding atmosphere in a rising fire plume has the effect of:
Correct Answer: D

The entrainment of air from the surrounding atmosphere into a rising fire plume will increase the total mass and volume of the plume. This is because more air is being added to the plume. This additional air cools the plume because the entrained air is relatively cooler than the fire plume. Additionally, the added air will dilute the concentration of fire products within the plume.

Question 8 of 99
During which stage of a fire would the heat release likely to be controlled by the fuel package size and geometry (i.e. the surface area likely to burn)?
Correct Answer: C

The heat release is likely controlled by the fuel package size and geometry during the Steady-state Stage. At this stage, the fire has reached a consistent burning rate, and the rate of heat release is predominantly influenced by the available fuel and its configuration.

Question 9 of 99
Which of the following materials is considered by NFPA to be a Group A plastic?
Correct Answer: A

According to the National Fire Protection Association (NFPA), Group A plastics are materials that generally include most thermoplastics with a tendency to burn readily. Butyl rubber fits this category as it is a synthetic rubber that can be easily ignited and continues to burn. Hence, of the given options, butyl rubber is considered by NFPA to be a Group A plastic.

Question 10 of 99
Which of the following refrigerants has the highest flammability, according to its Safety Group classification?
Correct Answer: D

Methane is classified under Safety Group A3, which indicates high flammability, according to ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards. In contrast, Octaflouropropane and Difluoromethane are less flammable, and Methyl Chloride, while being flammable, does not have the highest flammability compared to Methane.