Firefighter Practice Exam

In terms of heat behavior, what happens to air when heated?

1. It becomes denser and sinks

2. It expands and rises

3. It remains unchanged

4. It cools quickly

The correct answer is: It expands and rises

When air is heated, its molecular activity increases, which causes the air to expand. This expansion means that the air becomes less dense than the surrounding cooler air. As a result, the heated air rises. This principle is fundamental to understanding how convection currents work, both in a natural environment and in scenarios relevant to firefighting, such as smoke movement in a structure fire. The behavior of heated air is critical in firefighting since it can influence the spread of fire and smoke, as well as decisions about ventilation and escape routes. Understanding this property helps firefighters predict how smoke will travel through a building and where to direct their firefighting efforts effectively.