Automobile Fundamentals and Workshop Practice
This domain tests how a vehicle is laid out, how power reaches the road, and whether you can work safely and measure accurately in a workshop. Expect questions on chassis and body types, major assemblies, fasteners, jacking safety, and basic load calculations.
Core layout and terms
- A vehicle combines engine, transmission, suspension, steering, brakes, electrical system, and body/chassis. The chassis carries mechanical loads; the body encloses occupants and cargo.
- Common layouts are front-engine front-wheel drive (FWD), front-engine rear-wheel drive (RWD), rear-engine, and all-wheel drive. FWD saves space and weight; RWD separates steering from driving forces.
- Kerb weight is unladen weight with fluids; gross vehicle weight (GVW) adds payload. Payload is not the same as towing capacity.
- Workshop safety: chock wheels, use jack stands rather than a jack alone, wear eye protection, keep loose clothing away from rotating parts, and disconnect the battery before electrical work.
Worked example
A hydraulic jack raises a 1,200 kg car. Each jack stand is rated 1.5 tonnes. Is two stands enough? Vehicle weight = 1,200 × 9.81 ≈ 11,772 N ≈ 1.2 tonnes. Shared between two stands, that is about 0.6 tonne each, below 1.5 tonnes. But during lifting one end may carry most of the load, so stands must be rated for the axle load and placed on correct chassis points. The reasoning is: calculate load, compare with rating, then apply a safety margin and stable placement.
Traps that cost marks
- Using an adjustable wrench where a six-point socket fits; rounded nuts lose practical marks.
- Quoting GVW when the question asks for kerb weight.
- Measuring with a vernier without checking zero error.
- Working under a vehicle supported only by a jack.
- Ignoring battery isolation before wiring work.