How the EIAT Mechanical Aptitude section works
The EIAT is a paper test of 100 multiple-choice questions, and 35 of them are Mechanical Aptitude. Every question is a picture: two gears, a rope over a pulley, a plank on a pivot, two ladders. Under it is one question and three answers. The first two usually name the two things in the drawing (A or B, left or right) and the third says they are the same: "No difference", "Either A or B", "Both left and right".
NEIEP’s study guide lists what to revise: the basic machines (levers, pulleys and gears), hydraulics including area and pressure, and fulcrums and levers, including how objects of different weights balance. You do not need to know anything about elevators. The guide says the test measures your aptitude for the trade, not what you already know about it.
There is no separate pass mark for this section. The 70% line is counted over all 100 questions, so a weak mechanical section has to be made up in reading and maths.
How to answer a mechanical question
Take each drawing in this order:
- Read the question first, so you know which part of the drawing matters.
- Find the part that moves first: the driving gear, the hand on the rope, the weight on the lever.
- Follow the motion one part at a time, saying the direction of each to yourself.
- Name the rule that decides it: meshing gears, a crossed belt, weight times distance, pressure shared through a fluid.
- Before you choose the third answer, name the one thing that differs between A and B and ask whether it changes the result. If it does not, the third answer is right.
Worked examples
Belts. Two wheels are joined by a belt that crosses over itself between them. The left wheel turns clockwise. Which way does the right wheel turn? A: clockwise. B: counterclockwise. C: it does not turn. A crossed belt reverses the direction, so the answer is B. With an open belt the two wheels would turn the same way.
Gears. Three gears sit in a row, each meshing with the next. Gear 1 turns clockwise. Which way does gear 3 turn? A: clockwise. B: counterclockwise. C: it cannot turn. Gear 2 turns the opposite way to gear 1, counterclockwise, and gear 3 the opposite way to gear 2, clockwise. The answer is A. Count the gears: odd-numbered gears in a chain all turn the same way as the first.
Levers. A plank balances on a pivot. A 60 lb weight sits 2 feet to the left of the pivot. How much weight, placed 6 feet to the right, balances it? A: 20 lb. B: 30 lb. C: 60 lb. Weight times distance must match on both sides: 60 x 2 = 120, and 120 ÷ 6 = 20. The answer is A.
Hydraulics. In a closed hydraulic system, a small piston of 2 square inches is pushed down with 30 lb. The large piston is 10 square inches. What force does it lift? The pressure is 30 ÷ 2 = 15 lb per square inch everywhere in the fluid, so the large piston lifts 15 x 10 = 150 lb. The larger piston gets the larger force, and moves the shorter distance.
Tips for the real test
- Learn the handful of rules that carry most questions: meshing gears turn opposite ways, a crossed belt reverses direction, the smaller of two linked wheels turns faster, more rope sections holding a load mean less pull.
- Treat the third answer as a real answer. NEIEP’s own sample about two ropes moving a box is keyed "No difference".
- Draw arrows on the picture. The test is on paper, so mark each gear’s direction as you go rather than holding it in your head.
- Do not stall. The time limit is not published, and a question you sit on costs time the reading and maths sections need.
- Answer every question. NEIEP does not say whether a wrong answer costs marks, and a blank is never right.
Practise EIAT Mechanical Aptitude on CogniPrep
Our practice is 35 drawings of gears and belts, pulleys, levers and balance, and hydraulics, generated fresh for every sitting and getting harder as you go, each with three choices. There is no time limit: the clock counts up, and a marker at about 21 minutes shows this section’s share of the 60 minutes prep sites report for the whole paper, labelled reported, not official. You can skip, go back and hand in from a review grid. Your result is the percentage correct against the 70% line, with the topic that let you down named when one stands out. It is free with an account.