Electrical Engineering
Circuits, machines, power systems and electromagnetics: from Ohm's law to the smart grid.
106 topics: 37 beginner, 35 intermediate, 34 advanced.
About this discipline
Electrical engineering is about generating, moving and using electrical energy and information. It covers everything from the charge and current in a single resistor to the transmission grids that supply whole countries.
The course starts with voltage, current and resistance, then covers circuit analysis, AC power, magnetism and machines, power systems, and finally power electronics, renewables and electromagnetic waves.
Who it is for
Electrical and electronics students, electricians moving into design, and engineers in power, energy, automation or building services.
How the levels build
Beginner topics cover charge, Ohm’s law, circuits, capacitors, inductors and basic safety. Intermediate topics cover AC analysis, phasors, power factor, transformers, motors and three-phase systems. Advanced topics cover grids, protection, power electronics and electromagnetics.
Use cases
- Sizing cables, fuses and breakers for a building circuit.
- Correcting the power factor of a factory with capacitors.
- Choosing a motor and drive for a pump or conveyor.
- Designing a battery and inverter for a solar installation.
Beginner Electrical Engineering
Topic 1Electric chargeThe fundamental property of matter that causes electric forces; measured in coulombs.Topic 2CurrentThe rate of flow of charge, I=dQ/dt, measured in amperes.Topic 3VoltageEnergy per unit charge between two points; the push that drives current.Topic 4ResistanceOpposition to current flow, measured in ohms; depends on material, length and area.Topic 5Ohm's lawV=IR relates voltage, current and resistance in a resistor.Topic 6Electric powerP=VI watts; in a resistor P=I²R=V²/R.Topic 7Energy and kilowatt-hoursEnergy is power times time; household energy is billed in kWh.Topic 8Series circuitsComponents share the same current and voltages add.Topic 9Parallel circuitsComponents share the same voltage and currents add.Topic 10Kirchhoff's current lawCurrents entering a node sum to zero because charge is conserved.Topic 11Kirchhoff's voltage lawVoltages around any closed loop sum to zero because energy is conserved.Topic 12Voltage and current dividersSimple formulas give how voltage or current splits among resistors.Topic 13Resistor colour code and toleranceBands encode resistance value and accuracy.Topic 14Batteries and internal resistanceReal sources have internal resistance that drops terminal voltage under load.Topic 15Conductors, insulators and semiconductorsClassified by how freely charges move, described by band gap.Topic 16CapacitorsStore energy in an electric field; I=C dV/dt.Topic 17InductorsStore energy in a magnetic field; V=L dI/dt.Topic 18Series and parallel capacitors and inductorsCapacitors add in parallel while inductors add in series.Topic 19Electric fields and Coulomb's lawForce between charges is kq1q2/r².Topic 20Magnetic fieldsProduced by moving charges; magnetic flux density is measured in tesla.Topic 21Faraday's lawA changing flux induces EMF, ε=-dΦ/dt.Topic 22Lenz's lawInduced current opposes the change that produced it.Topic 23Safety and groundingEarthing and protective devices prevent shock and fire.Topic 24Fuses and circuit breakersInterrupt excess current to protect wires and equipment.Topic 25Measuring instrumentsMultimeters and oscilloscopes measure voltage, current, resistance and waveforms.Topic 26Node-voltage analysisApply KCL at nodes to solve for node potentials.Topic 27Mesh-current analysisApply KVL around loops to solve for loop currents.Topic 28Superposition theoremIn linear circuits the response is the sum of responses from each source acting alone.Topic 29Thevenin equivalentAny linear network looks like a voltage source in series with a resistance from two terminals.Topic 30Norton equivalentA current source in parallel with a resistance equivalent to the network.Topic 31Maximum power transferLoad receives maximum power when its resistance equals the source resistance.Topic 32Star-delta transformationConverts between three-resistor configurations to simplify networks.Topic 33Dependent sourcesSources controlled by another voltage or current; used to model transistors and amplifiers.Topic 34RC circuit transientCapacitor charges with time constant τ=RC, reaching 63% in one τ.Topic 35RL circuit transientCurrent rises with time constant τ=L/R.Topic 36RLC circuit responseSecond-order circuit that can be over-, critically or under-damped.Topic 37Sinusoidal ACVoltage varies as V sin(ωt); frequency f and period T describe repetition.
Intermediate Electrical Engineering
Topic 38RMS valueThe DC-equivalent heating value of an AC waveform; Vrms=Vpeak/√2 for a sine.Topic 39PhasorsComplex numbers representing amplitude and phase of sinusoids, turning calculus into algebra.Topic 40ImpedanceComplex opposition to AC: Z=R+jX with reactances jωL and 1/jωC.Topic 41ReactanceInductive and capacitive opposition that depends on frequency.Topic 42Power in AC circuitsReal power P, reactive power Q and apparent power S relate by S²=P²+Q².Topic 43Power factorcosφ shows how much current does useful work; low values waste capacity.Topic 44Power factor correctionCapacitor banks cancel inductive reactive power to raise power factor.Topic 45Resonance in RLC circuitsAt ω0=1/√(LC) reactances cancel and a series circuit has minimum impedance.Topic 46Quality factorQ measures sharpness of resonance and energy stored versus lost.Topic 47FiltersCircuits that pass or block frequency bands: low-pass, high-pass, band-pass and notch.Topic 48Frequency response and Bode plotsLog plots of gain and phase against frequency.Topic 49Two-port networksBlack-box models using Z, Y, h or ABCD parameters.Topic 50Mutual inductanceCoupling between coils through shared flux, basis of transformers.Topic 51TransformersChange AC voltage with turns ratio V1/V2=N1/N2.Topic 52Transformer efficiency and lossesCopper and core losses reduce efficiency; regulation describes voltage drop under load.Topic 53Three-phase systemsThree voltages 120° apart deliver smoother, more efficient power.Topic 54Star and delta connectionsLine and phase quantities differ by √3 in balanced three-phase systems.Topic 55Three-phase power measurementTotal power measured using two-wattmeter or per-phase methods.Topic 56Electromagnetic induction in machinesMotion of conductors in magnetic fields generates voltage.Topic 57DC generatorsConvert mechanical energy into DC using commutators.Topic 58DC motorsTorque is proportional to flux and armature current; speed is controlled by voltage.Topic 59DC motor typesShunt, series and compound motors have different speed-torque behaviours.Topic 60Induction motorsRotating stator field induces rotor current; slip enables torque.Topic 61Synchronous machinesRotor runs at synchronous speed Ns=120f/P; used as generators and for power factor control.Topic 62Single-phase motorsUse capacitors or shading coils to create starting torque.Topic 63Stepper and BLDC motorsPrecisely controlled brushless machines used in robotics and drives.Topic 64Motor starting methodsStar-delta, soft starters and drives limit inrush current.Topic 65Variable frequency drivesInverters vary supply frequency to control AC motor speed efficiently.Topic 66Power generation methodsThermal, hydro, nuclear, wind and solar convert energy sources to electricity.Topic 67Transmission linesHigh voltage reduces current and losses over long distances.Topic 68Per-unit systemNormalises quantities to base values for easier power-system calculations.Topic 69Line parametersResistance, inductance, capacitance and conductance characterise lines.Topic 70Distribution systemsStep voltage down to consumers through feeders and substations.Topic 71Load flow analysisNumerical solution of voltages and power flows across the grid.Topic 72Fault analysisCalculates short-circuit currents; symmetrical components handle unbalanced faults.
Advanced Electrical Engineering
Topic 73Symmetrical componentsDecompose unbalanced phasors into positive, negative and zero sequences.Topic 74Protective relaysDetect faults and trip breakers selectively.Topic 75Circuit breaker typesAir, vacuum, oil and SF6 breakers extinguish arcs differently.Topic 76Power system stabilityAbility of generators to remain synchronised after disturbances.Topic 77Frequency controlMatching generation to load keeps grid frequency near 50 or 60 Hz.Topic 78Reactive power and voltage controlVoltage is regulated with capacitors, reactors and tap changers.Topic 79HVDC transmissionDC links carry bulk power over long distances with low losses.Topic 80Renewable integrationVariable wind and solar need storage, forecasting and flexible grids.Topic 81Solar photovoltaic systemsCells convert sunlight into DC power, with MPPT maximising output.Topic 82Wind turbinesExtract kinetic energy of wind with efficiency limited by the Betz limit of 59%.Topic 83Energy storageBatteries, pumped hydro and flywheels balance supply and demand.Topic 84Smart gridsCombine sensing, communication and control for a reliable, flexible grid.Topic 85MicrogridsLocal grids that can operate connected to or isolated from the main grid.Topic 86Electric vehicles and chargingEVs add flexible load and storage; chargers need power electronics and standards.Topic 87Power electronics convertersSwitch-mode circuits convert and control electrical power efficiently.Topic 88RectifiersConvert AC to DC using diodes or thyristors.Topic 89DC-DC convertersBuck, boost and buck-boost regulate DC voltage using inductor switching.Topic 90InvertersConvert DC to AC using PWM switching.Topic 91Thyristors and IGBTsPower semiconductor switches for high voltage and current.Topic 92Electromagnetic wavesCoupled electric and magnetic fields travelling at the speed of light.Topic 93Maxwell's equationsFour laws unifying electricity, magnetism and light.Topic 94Poynting vectorGives direction and rate of energy flow of an electromagnetic wave.Topic 95Transmission line theoryWave behaviour on lines with characteristic impedance and reflections.Topic 96Smith chartGraphical tool for impedance matching on transmission lines.Topic 97Waveguides and antennasGuide and radiate electromagnetic energy at microwave frequencies.Topic 98Electromagnetic compatibilityDesigning equipment to avoid interference and tolerate it.Topic 99Insulation and dielectric breakdownInsulating materials fail when field exceeds dielectric strength.Topic 100Electrical wiring and standardsCodes specify cable sizing, protection and installation practice.Topic 101Earthing systemsTN, TT and IT systems define how neutral and exposed parts connect to earth.Topic 102Lightning and surge protectionArresters and shielding divert transient overvoltages safely.Topic 103Electrical measurements and sensorsCTs, PTs and transducers scale high values to measurable signals.Topic 104Energy auditing and efficiencyIdentify and reduce losses in electrical systems.Topic 105Power quality and harmonicsNonlinear loads distort waveforms; THD and filters keep voltage clean.Topic 106Grid-forming invertersInverters that set voltage and frequency, enabling grids with high renewable share.
Frequently asked questions
What is Electrical Engineering?
Circuits, machines, power systems and electromagnetics: from Ohm's law to the smart grid.
How many topics are in Electrical Engineering?
106 topics, ordered from beginner to advanced: 37 beginner, 35 intermediate and 34 advanced.
Where should a beginner start in Electrical Engineering?
Start with "Electric charge" and work through the list in order. Each topic builds on the one before it.
Why does AC power use RMS values?
RMS gives the DC equivalent heating effect, so a 230 V mains supply delivers the same heating power as 230 V DC would.
What is the most common mistake in circuit analysis?
Mixing up sign conventions for voltage and current. Choose directions first, apply the same rule everywhere, and check the sign of the result.
Why is high voltage used for transmission?
Higher voltage means lower current for the same power, so the resistive losses in the line fall rapidly.
Is electrical safety just common sense?
No. Standards define earthing, protection and wiring rules, and they exist because electric shock and fire hazards are easy to underestimate.
Where do electrical engineers work?
In power utilities, manufacturing, buildings, electric transport, telecoms, renewable energy and consumer electronics.
Practise in the interactive course with quizzes, tests and labs.