// Free practice · Navy · RAF
Free DAA Mechanical Comprehension test
Ten Mechanical Comprehension questions in the format of the Defence Aptitude Assessment – gears, levers, pulleys and forces.
- 10 questions
- 7 minutes
- Timed
What Mechanical Comprehension looks like
Mechanical comprehension is one of the six DAA tests (RAF). In our practice the questions cover gears, levers, pulleys and simple forces – which way a gear turns, how fast it turns, where the pivot of a lever sits.
Two touching gears always turn in opposite directions, and the smaller gear always turns faster. Speed of the driven gear = speed of the driver × teeth on the driver ÷ teeth on the driven gear.
How this free test is set up
Ten questions in seven minutes – about half of our practice timing of 19 questions in 13 minutes. The services do not publish exact numbers for the real test; the timing is practice.
This free test is being built.
Meanwhile, try the sample questions on the course page.
No sign-up, no e-mail. Original questions written in the format of the real test, with an explanation for every answer. Updated 23 October 2026.
More free practice
- The fastest-paced part of the DAA is in the free DAA Work Rate test.
- All six sections step by step and as a full mock are in the Defence Aptitude Assessment course.
- Preparing for a different service? Try the Army Cognitive Test (ACT) sample questions.
- Preparing for a different service? Try the SIA Door Supervisor sample questions.