# Mechanical Comprehension Tests

Mechanical comprehension tests measure your knowledge of mechanical and physical concepts including: LeversPulleysGearsSpringsSimple Electrical CircuitsTools and Shop Arithmetic.

Modern mechanical comprehension tests often include fault diagnosis questions which are used to select personnel for technical roles where they need to be able to find and repair faults in electronic control systems. The questions in fault diagnosis tests appear rather abstract and require pure logic to solve. This is because when a fault develops in an electronically controlled system, there is often no physical clue as to the cause. In the absence of such a clue, for example an obviously burned-out component, the only way to diagnose the problem is by a process of logical elimination. This type of test is used extensively to select technical and maintenance personnel as well as to select for artificer (technical) roles within the armed forces where the ability to approach problems logically in order to find the cause of the fault is increasingly important.

If you are taking a mechanical comprehension test as part of the selection process for the emergency services or the military then the questions you can expect will tend to concentrate on principles rather than on making calculations. For example, you may be shown 3 diagrams of a lever and asked which one is the most efficient. If however, you are taking a test for a craft or technical job then you may be expected to calculate the actual force required to move a particular lever. In this case, knowing the principle is not enough, you need to know the formula.

Example Mechanical Comprehension Test Questions

1) How much weight is required to balance the lever?

• A) 15kg

• B) 5kg

• C) 10kg

• D) 7.5kg

• E) 20kg

2) How much weight is required to balance the lever?

• A) 30lbs

• B) 25lbs

• C) 28lbs

• D) 40lbs

• E) 35lbs

3) Approximately how much force is needed to lift the weight?

• A) 24lbs

• B) 10lbs

• C) 48lbs

• D) 12lbs

• E) 18lbs

4) If gear X turns clockwise at a constant speed of 10 rpm. How does gear Y turn?

• A) anti c/w 10 rpm

• B) c/w 10 rpm

• C) c/w 5 rpm

• D) anti c/w 5 rpm

• E) c/w 20 rpm

5) If drive wheel X rotates clockwise at a speed of 10 rpm. How does wheel Y turn?

• A) anti c/w faster

• B) c/w slower

• C) c/w faster

• D) anti c/w slower

• E) anti c/w same

6) A force of 5 Kg compresses the springs in series 10cm. What will be the total distance that the springs in parallel are compressed?

• A) 10 cms

• B) 5 cms

• C) 20 cms

• D) 7.5 cms

• E) 15 cms

7) In the circuit shown, how many switches need to be closed to light up one bulb?

• A) None

• B) One

• C) Two

• D) Three

• E) Four

8) Which is the most suitable tool for breaking up concrete?

• A) None

• B) 1

• C) 2

• D) 3

• E) 4

9) Which tool or combination of tools would be most useful for general woodwork?

• A) 4 & 2

• B) 3,5 & 7

• C) 2 ,4  & 6

• D) 4 & 7

• E) 3 & 6

10) The sketch shows the floor plan of a bathroom. The shower tray is 2'6" square and is fixed to the floor. The toilet and washbasin are both wall mounted. Allowing for 15% wastage, approximately how many square yards of floor tiles should be ordered?

• A) 7.25

• B) 6.25

• C) 9.25

• D) 5.50

• E) 8.50

The answers to these questions are given at the bottom of the page.

Many of the questions in mechanical comprehension tests are ‘industry’ specific. For example, tests used by the fire service tend to frame the questions in terms of fire-fighting whereas tests used to select for an aircraft maintenance job would tend to frame the questions in aviation industry terms. It doesn’t matter if the questions you practice on aren’t specific to the industry you are applying for. It is the substance of the question that is important – the scenario is incidental.

These sample question papers each contain 40 questions and have a suggested time limit of 30 minutes each. The questions are presented in Letter/A4 format for easy printing and self-marking.