Mechanical aptitude test practice

Start with the diagram

Find the part that supplies motion or force. Read the labels, arrows and units. Decide what is fixed and what can move. Then follow the effect one connection at a time.

Three useful starting rules

These are starting models; read each question’s assumptions before applying them.

1. Gears: two touching external gears turn in opposite directions. Compare tooth counts to compare speeds.
2. Levers: compare force multiplied by perpendicular distance from the pivot on each side.
3. Pulleys: count the rope segments supporting the moving load in an ideal system, not just the number of wheels.

Move from the lab to a still picture

Change one setting in an interactive lab, predict the result, then check what happens. Next, try a practice question with a still diagram. Explain the relationship in words so you can use it when the picture changes.

Use a worked example

A 12-tooth driver turns an external 24-tooth gear at 60 RPM. The driven speed is 60 × 12 ÷ 24 = 30 RPM, in the opposite direction. The larger gear turns more slowly because each full turn requires more teeth to pass the contact point.

Lessons to start with

• Forces & Moving in a Circle — Pushes, pulls, and what happens when you let go
• Levers & Sharing a Load — How distance from the pivot changes the result
• Pulley Systems — Use less pull by moving more rope
• Gears: Direction & Speed — Which way gears turn and how fast they move

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Common questions

Official applicant resources

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