Electrotechnology (Stage 6 VET Board Endorsed Course)
Core electrical principles
This course builds on the fundamental relationship between voltage, current and resistance. Ohm's law (V = IR) and the power equation (P = VI, also P = I²R and P = V²/R) underpin almost every calculation. Understand the difference between DC and AC, the meaning of RMS values, and why mains supply is described by both voltage and frequency (nominally 230 V, 50 Hz in Australia).
Circuits and components
Know series versus parallel behaviour: current is common in series, voltage is common in parallel. Be able to calculate total resistance, branch currents and voltage drops. Recognise common components - resistors, capacitors, inductors, diodes, switches, relays, fuses and circuit breakers - and their circuit symbols and functions. Understand why protective devices are rated to interrupt fault current and why earthing and residual current devices matter for safety.
Measurement and safety
Candidates must know how a multimeter is used to measure voltage (in parallel), current (in series) and resistance (with power isolated). Traps often appear here: a meter set to the wrong range, or an ammeter connected across a supply, causes a short circuit. Always isolate and prove dead before working, and understand the meaning of lock-out/tag-out.
Traps to watch
Questions frequently test unit prefixes (milli, kilo, mega), the difference between power and energy (watts versus watt-hours), and the distinction between a.c. peak and RMS values. Read the unit in the stem carefully - a common error is mixing mA with A.
Worked example
A 12 V supply drives two 6 Ω resistors in parallel. Total resistance = (6×6)/(6+6) = 3 Ω. Total current = V/R = 12/3 = 4 A. Each branch carries 2 A. Power = VI = 12 × 4 = 48 W. Rule of thumb: for two equal resistors in parallel, total resistance is half of one.