Mec-A5 — Electrical and Electronics Engineering
DC circuits, Single phase and polyphase circuits Magnetic circuits and transformers (ideal and practical), DC machines: motors and generators. AC machines: induction motors, synchronous motors, and alternators. Power factor correction. Analogue and digital semiconductor devices. Transistor amplifiers and switches. Power semiconductor devices, rectifiers, DC power supplies and voltage regulation. Operational amplifiers and application circuits. Combinational and sequential digital logic circuits. Practical approach to electronic instrumentation, measurement systems and transducers.
Subject outline
Mec-A5 Electrical and Electronics Engineering is a Mechanical Engineering technical exam (PEO National Examination 16-Mec-A5) covering the electrical and electronic engineering a mechanical engineer is expected to be able to do: dc circuit analysis and the network theorems, the transient response of RC and RL circuits, ac circuits with phasors, real and reactive power and power-factor correction, semiconductor devices and BJT biasing, small-signal analysis, operational amplifiers, digital logic from Boolean algebra and truth tables through minimisation to gate realisations, magnetic circuits and transformers, and rotating machines — dc machines and induction motors alike. The official syllabus also lists polyphase circuits, conventional dc motors and generators, synchronous motors and alternators, power semiconductors, rectifiers and dc power supplies, sequential logic, and instrumentation and transducers; this course is built on the two 2019 papers and does not cover those topics in depth.
The paper is 3 hours and closed book; the rubric permits one of two approved calculators, the Casio or the Sharp. Nothing whatever may be taken in — no tables, no formula sheet and no aid sheet. Unlike most PEO papers, this one attaches no tables of any kind and gives you nowhere to write anything down beforehand, so the formulae have to be in your head. The only data supplied are three constants printed on the front page: π = 3.14159, 1 hp = 746 W and μ₀ = 4π × 10⁻⁷ H/m. Answer any five of the eight questions: any five constitute a complete paper, only the first five as they appear in the answer book are marked, and all questions are of equal value at 20 marks. No mark split is printed anywhere inside a question, so treat the parts as sharing the 20 evenly and never leave one blank — and clarity and organisation of the answers are explicitly marked.
The same examination is also listed as 08-Mfg-A7 (Manufacturing Engineering) — same paper, same syllabus, two faculty codes. The question papers are headed 16-Mec-A5; some of the downloadable sheets in this course carry the 08-Mfg-A7 heading.
What this course gives you
Worked solutions — all sixteen questions from May 2019 and December 2019, solved in full, with every published answer independently recomputed — and thirty separate findings flagged where the published work does not hold up. Where a published figure stands it is used; where it does not, the published value is quoted and a flagged correction of its own — headed, and set into the working at the exact step that goes wrong — explains what went wrong and gives the corrected value. There are thirty such corrections across all sixteen questions, and nothing has been silently overwritten. The largest findings: the December Q3(b) disc-machine torque is derived from the current-loop formula on a machine whose current runs radially and encloses no area, which makes it 2π times too large and breaks the power balance; the rotor-current frequency is computed as (1−s)f = 58.2 Hz when it is sf = 1.8 Hz; an 8-pole motor is treated as 4-pole and the resulting "operating point" assigns the motor and the load different torques at one speed — it is 870 rpm at 1.00 N·m; a transducer on the secondary is never referred to the primary, giving 0.278 Ω where the answer is 8.0 Ω; and three parts of December Q5 are not answered at all — they are authored here in full. Two papers, and that is the whole set — three sittings exist, but December 2018 and December 2019 are the same paper question for question, with identical numbers in all eight questions, and May 2019 shares their transformer question. Working these two covers everything available; there is no third paper being held back. Study notes — eleven condensed topics: how this paper works; dc circuit analysis and the network theorems; the transient response of RC and RL circuits; ac circuits, phasors and power; semiconductor devices and BJT biasing; small-signal analysis; operational amplifiers; digital logic in two parts, algebra and minimisation and then gate realisations; magnetic circuits and transformers; and rotating machines — each pointing back at the exam questions it answers. Practice & case studies — ten multiple-choice questions and five longer problems, the last of them a motor-drive case study, with worked answers for every one. Formula sheet — two pages of the core circuit laws, device models and machine equations the two papers use. This exam allows no aid sheet and attaches no tables, so this sheet is for the week before, not for the exam hall. Printable resources — ten cards, including a "which method do I use?" decision table and the checks that catch the very errors this pack found, plus four blank exam stationery templates. Practice papers — the two question papers on their own, unmarked, for a timed run: May 2019 and December 2019, the same two sittings that are solved above.
Throughout, 116 figures were drawn for this pack — 58 in the solutions and 58 in the notes — alongside 12 crops taken from the original question papers, so the circuits, waveforms, phasor diagrams, load lines, Bode plots, gate networks and machine characteristics are shown rather than described.