How the ACER mechanical reasoning test works
Fire Rescue Victoria’s Written Selection Test has four sub-tests: literacy, abstract reasoning, numeracy and mechanical reasoning. The mechanical section is 32 questions in 20 minutes, about 37 seconds each, on seven topics: wheels and belts, gears, linked bars, simple machines, fluids and pressure, levers and pulleys, and forces and motion.
ACER says it tests your understanding of very basic physics and mechanics, your ability to picture objects moving in three dimensions, and cause and effect between mechanical parts.
You must pass all four sub-tests, and only the highest-ranking candidates go on to FRV’s group assessment. When an employer buys the MRT on its own, ACER reports a raw score out of 32 as a percentile and a stanine against Australian adult norms from 2010 to 2011.
How to answer mechanical questions
Name the mechanism first, then apply its rule:
- Gears: meshed gears turn opposite ways. The gear with fewer teeth turns faster.
- Belts: an open belt keeps both wheels turning the same way; a crossed belt reverses the second.
- Levers: the longer the arm you push on, the less force you need.
- Pulleys: the more rope sections hold the load, the less force you need and the more rope you pull.
- Fluids: pressure in a closed system acts equally in every direction.
- Picture the first part moving and follow it through the mechanism one link at a time before you look at the options.
Worked example
Gear A has 12 teeth and turns clockwise at 60 turns a minute. It drives gear B, which has 36 teeth. Which way does B turn, and how fast?
Meshed gears turn opposite ways, so B turns anticlockwise. B has three times as many teeth, so it turns a third as fast: 60 × 12 ÷ 36 = 20 turns a minute. If a third gear meshed with B, it would turn clockwise again.
Tips for the real ACER mechanical reasoning test
- Learn the rules for the seven listed topics. They cover the paper, so there is nothing else to revise.
- Keep to about 37 seconds a question. If the mechanism has not made sense in 15 seconds, take your best answer and move on.
- Answer every question. ACER states that points are not deducted for incorrect answers.
- Practise from diagrams. The real questions are drawings, and reading them quickly is half the skill.
- Mechanical reasoning is one of four FRV sub-tests, and failing any one stops you, so do not neglect the other three.
Practise ACER mechanical reasoning on CogniPrep
Our ACER Mechanical Reasoning test is 32 questions in 20 minutes across the same seven topics, with five options each and nothing deducted for a wrong answer. Two differences matter. Our questions describe each mechanism in words rather than drawing it, so add some diagram practice before the day. And choosing an answer moves you on, with no way back, while the real test lets you return to questions. Questions come from a bank of 92, easiest first, and you get a score out of 100.