Free OFAI Situational and Technical Knowledge Questions and Answers

Question 1

Which of the following liquids has the highest explosive range?

Accepted Answer

Ethanol

Answer

Explanation:
Ethanol has the highest explosive range among the options provided. It forms explosive mixtures with air over a wide concentration range, making it highly flammable and prone to ignition. Understanding the properties of different fuels, including their explosive ranges, is crucial for firefighters to effectively manage fire incidents and ensure safety during firefighting operations.

Question 2

Which of the following liquids had the lowest vapor density?

Accepted Answer

Ethanol

Answer

Explanation:
Ethanol has the lowest vapor density among the options provided. Vapor density is a measure of a substance's weight compared to an equal volume of air, and substances with lower vapor density tend to evaporate more readily and form flammable vapor-air mixtures at lower concentrations. Understanding the vapor density of various liquids is essential for firefighters to assess fire hazards and determine appropriate firefighting strategies.

Question 3

Which of the following liquids has the highest specific gravity?

Accepted Answer

Kerosene

Answer

Explanation:
Kerosene typically has a higher specific gravity compared to the other liquids listed. Specific gravity is the density of a substance compared to the density of water. Substances with higher specific gravity sink in water. Understanding the specific gravity of different liquids is essential for firefighters as it helps them assess fire hazards and determine appropriate firefighting strategies, such as selecting the right extinguishing agents.

Question 4

Which of the following descriptions is correct?

Accepted Answer

Class B Fires - Flammable liquids, gases

Answer

Explanation:
Class B fires involve flammable liquids and gases. These fires are characterized by substances such as gasoline, oil, grease, and propane. Understanding the classification of fires is essential for firefighters to determine the appropriate extinguishing agents and firefighting techniques required to safely and effectively extinguish different types of fires.

Question 5

Fires which involve such metals as sodium, magnesium, titanium, aluminum, and uranium are classified as _____________ fires.

Accepted Answer

Class D

Answer

Explanation:
Class D fires involve combustible metals such as sodium, magnesium, titanium, aluminum, and uranium. These fires require specialized extinguishing agents and firefighting techniques due to the unique properties and challenges associated with combating metal fires. Understanding the classification of fires is crucial for firefighters to effectively respond to and extinguish different types of fire emergencies.

OFAI - Firefighter Aptitude Test Ontario Practice Test

OFAI - Firefighter Aptitude Test Ontario Practice Test

Free OFAI Situational and Technical Knowledge Questions and Answers