How the Mechanical Reasoning test works
The test has 21 questions on one 10-minute clock, which leaves under 30 seconds each. Each one pairs a picture with a short question, such as which support carries the most load, which spanner needs more force or which gear spins faster, and three or four options. One option is usually that they are all the same or that nothing changes.
The three skill areas are tested equally, so expect about seven questions on each: force and movement, velocity, and pulleys, gears and wheels. TestGorilla pitches the test at entry level and suggests it for technicians, electricians, welders, plumbers, machinists, mechanics and engineers.
The principles behind most questions
A handful of rules answer most of the test:
- Levers and spanners: what turns a bolt is force times distance from the pivot. A longer handle needs less force.
- Beams on two supports: the support nearer the load carries more of it.
- Gears: meshed gears turn in opposite directions, and the gear with fewer teeth turns faster, in proportion to the teeth.
- Belts: an open belt keeps both wheels turning the same way; a crossed belt reverses one. The smaller wheel turns faster.
- Pulleys: the more rope sections hold up the load, the less force you need, but the more rope you pull.
Worked examples
Gears. Gear A has 40 teeth and drives gear B, which has 10. Gear A turns clockwise at 30 revolutions per minute. Which gear turns faster: A, B, or both the same? And which way does B turn?
Each turn of A pushes 40 teeth past B, which is four full turns of B. So B is faster, at 4 × 30 = 120 revolutions per minute, and because meshed gears turn in opposite directions, B turns anticlockwise.
A beam. A 6 m plank rests on support X at the left end and support Y at the right end, with a 90 kg load 2 m from X. Which support carries more: X, Y, or both the same? X, because the load is nearer to it. Each support takes a share in proportion to the load’s distance from the other support: X carries 4/6 of 90 kg, which is 60 kg, and Y carries 2/6, which is 30 kg.
Tips for the real Mechanical Reasoning test
- Name the principle before you look at the options. Most questions turn on one rule, and the options are built to catch a guess based on looks.
- Pick “the same” only when the principle says nothing changes, not because you cannot decide.
- Count teeth and rope sections instead of judging sizes by eye.
- Keep moving: there is no going back, and 21 questions in 10 minutes allows no long stares.
- Guess rather than skip. A skip counts as wrong, and a guess on a three-option question has a one-in-three chance.
Practise Mechanical Reasoning on CogniPrep
Ours matches the published format: 21 questions on one 10-minute clock, seven from each skill area, most with a drawn diagram and three or four options. Questions come from our bank of 84, covering levers, beams, spanners, slopes, springs, gears, belts and pulley systems. One question per screen, no going back and a skip marked wrong, then a raw percentage, a percentile against CogniPrep players with harder questions weighted more, and feedback on each area.