Technology-Specific Core Engineering Subjects
What the examiner expects
Core engineering questions for Civil, Electrical, Mechanical and Computer streams test whether you can move between a physical situation, a governing relation, and a numerical answer. For Civil, know stress and strain, bending moment and shear force diagrams, concrete mix ratios, soil bearing capacity and surveying bearings. For Electrical, be fluent in Ohm's law, series-parallel networks, three-phase power relations, transformer turns ratio, and power factor. For Mechanical, revise thermodynamic laws, the Carnot efficiency, stress-strain behaviour of mild steel, gear ratios and Bernoulli's equation. For Computer, cover number systems, logic gates, Boolean simplification, and basic data structures.
Traps that recur
Unit mismatches are the most common failure: mm versus m in stress, kVA versus kW in power factor questions, and rpm versus rad/s in torque problems. Watch the difference between gauge and absolute pressure, between RMS and peak AC values, and between nominal and design mix concrete. In shear force and bending moment questions, the maximum bending moment rarely occurs where the maximum shear force does; candidates often mark the wrong section. In Boolean algebra, De Morgan's law is applied incorrectly when the bar is not carried over the whole expression.
Worked example
A three-phase induction motor draws 15 kW at 0.8 power factor lagging from a 400 V supply. Find the line current. Use P = √3 × V_L × I_L × cos φ, so I_L = 15000 / (1.732 × 400 × 0.8) = 27.1 A. Rule of thumb: always convert kW to W and confirm whether the given voltage is line or phase before substituting.
Revision strategy
Practise one numerical from each stream daily and write the formula before the substitution; examiners award method marks even when arithmetic slips.