SHLAptitude

Mechanical Comprehension practice test

Gear trains, belts, pulleys, levers and hydraulic rams — drawn properly, and answered with the ratio written out rather than guessed.

Free to start. Every item is generated fresh, marked with a full worked solution, and ranked on a 1–9 stanine band that recalibrates as more candidates practise.

6

mechanism families

3 min

timed run

1–9

stanine rank

What it measures

What Mechanical Comprehension is actually testing

Mechanical comprehension measures whether you can read a mechanism from a drawing and reason about what it does: which way something turns, how fast, how much force is needed, which way pressure moves. It rewards a handful of ratios applied cleanly, not a physics degree.

The format

How the real assessment runs

Format
A labelled diagram and a question about direction, speed, force or pressure. Four to five options, usually with units.
Mechanisms
Meshed gear trains, belt drives (open and crossed), compound gear ratios, pulley blocks, levers and hydraulic pistons.
Timing
Around 45–60 seconds an item. Enough to write the ratio down, not enough to derive it from first principles.
Marking
Number correct. Unit errors count as wrong answers, and the option list always contains one.

Where marks are lost

The trap that costs the most marks

Direction on belt drives, and inverting the ratio. A crossed belt reverses the driven wheel; an open one does not. And on any gear or pulley pair, the larger wheel turns slower but pulls harder — half of all wrong answers are the reciprocal of the right one, sitting in the option list waiting.

Why practise here

What this practice gives you

01

Six mechanism families with diagrams drawn from the real geometry — belt tangents computed, teeth counted, not sketched

02

Every answer shows the ratio written out, with the units carried through

03

Distractors include the inverted ratio and the wrong-unit answer, because those are the mistakes that actually happen

04

Direction questions on both open and crossed belts, which most free practice skips entirely

05

A stanine band so you know whether your score is competitive for a technical scheme

Where you will meet it

Who uses this format

Engineering apprenticeshipsMaintenance and technician rolesArmed forces and emergency servicesManufacturing and process industriesAviation ground and flight crew

Hiring stages where this format is commonly used. Persona Prep is not affiliated with SHL and does not reproduce their questions — we build practice in the same format, from our own generators.

With Persona Prep Pro

Everything you need to walk in ready

One subscription covers the whole assessment library, not just this exercise — because almost nobody is invited to sit only one module.

The full aptitude library

SHL Verify, Aon cut-e, Hogan and Saville formats — numerical, verbal, inductive, deductive, mechanical, checking and the interactive modules.

A rank, not just a score

Every run is placed on a 1–9 stanine band that recalibrates as the candidate pool grows, so you know your position.

A course per exercise

What it measures, the trap that costs marks, and worked items from every format — then the exercise itself.

Unlimited fresh items

Everything is generated, so you never run out and never memorise a bank.

Written + voice AI coach

Reads your results across exercises and tells you which two to fix first.

Personality practice too

SHL OPQ32, Hogan HPI/HDS/MVPI, Saville Wave, ADEPT-15 and 16PF, with full profile reports.

Mechanical Comprehensionfrequently asked questions

What is a mechanical comprehension test?

A mechanical comprehension test shows a labelled mechanism — gears, belts, pulleys, levers, hydraulics — and asks about direction, speed, force or pressure. It tests whether you can read a mechanism from a drawing and apply a small set of ratios cleanly, not whether you know physics formally.

How do gear and pulley ratio questions work?

For meshed gears, speed is inversely proportional to tooth count: the larger gear turns slower and delivers more torque. Meshed gears turn in opposite directions; a belt drive keeps direction unless the belt is crossed. About half of all wrong answers on these items are the reciprocal of the right one.

Which mechanisms does this practice cover?

Six families: meshed gear trains, open and crossed belt drives, compound gear ratios, pulley blocks, levers and hydraulic pistons. The diagrams are drawn from the real geometry — belt tangents are computed and teeth are counted — rather than sketched approximately.

Who has to take mechanical reasoning tests?

Engineering and maintenance apprenticeships, technician roles, armed forces and emergency services selection, manufacturing and process industries, and aviation ground and flight crew recruitment.

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