OFAI OFAI - Firefighter Aptitude Test Ontario Mechanical Aptitude and Physical Sciences Questions and Answers 1 — Questions and Answers
Question 1: A firefighter is using a lever to lift a heavy object. If the effort arm is 6 feet and the load arm is 2 feet, what is the mechanical advantage?
- 2
- 3 (Correct answer)
- 4
- 6
Correct answer: 3
Mechanical advantage equals the effort arm length divided by the load arm length: 6 ÷ 2 = 3.
Question 2: Water is being pumped through a hose. If the hose diameter is decreased, what happens to the water pressure at the nozzle?
- It decreases
- It stays the same
- It increases (Correct answer)
- It becomes zero
Correct answer: It increases
Reducing hose diameter increases water velocity and pressure at the nozzle due to the Venturi effect and conservation of energy.
Question 3: A pulley system has 4 rope segments supporting a load. What is the mechanical advantage of this system?
- 1
- 2
- 4 (Correct answer)
- 8
Correct answer: 4
In a block-and-tackle pulley system, the mechanical advantage equals the number of rope segments supporting the load.
Question 4: Which of the following best describes why a firefighter should not cut an electrical wire under tension?
- The wire may snap back and cause injury (Correct answer)
- The wire will lose its insulation
- The wire becomes magnetic when cut
- The wire will not conduct electricity after cutting
Correct answer: The wire may snap back and cause injury
A wire under tension stores potential energy and can snap back violently when cut, posing a serious injury risk.
Question 5: A fire engine pump is rated at 1,000 gallons per minute (GPM). If two hose lines each require 250 GPM, how many such lines can the pump fully supply?
- 2
- 3
- 4 (Correct answer)
- 5
Correct answer: 4
Dividing the total pump capacity (1,000 GPM) by the flow required per line (250 GPM) gives 4 fully supplied lines.
Question 6: What effect does increasing temperature have on the pressure inside a sealed container of gas?
- Pressure decreases
- Pressure stays the same
- Pressure increases (Correct answer)
- The gas condenses
Correct answer: Pressure increases
According to Gay-Lussac's Law, for a fixed volume of gas, pressure increases proportionally with absolute temperature.
OFAI OFAI - Firefighter Aptitude Test Ontario Mechanical Aptitude and Physical Sciences Questions and Answers 1
A firefighter is using a lever to lift a heavy object.
If the effort arm is 6 feet and the load arm is 2 feet, what is the mechanical advantage?