Elec Class
learn electricity hands-on
The whole basic electricity course, from units to alternating current. Each lesson has its own calculator, the key points to remember, a worked example and problems solved step by step.
SI system, prefixes, scientific notation, significant figures, IEC symbols, reading instruments.
Atom, charges, conductors and insulators, Coulomb's law, electric field.
Potential, p.d., current direction, quantity of electricity Q = I·t, current density, generation and distribution.
U = R·I, Pouillet's law, temperature effect, E12 series.
P = U·I, W = P·t, Joule heating, joule and kWh, efficiency of a power chain.
Series, parallel, mixed, equivalent resistance, line voltage drop.
EMF E and internal resistance r, back-EMF E' and r', generalised Ohm's law, U = f(I) characteristic.
Loop rule, junction rule, circuits with several sources.
Capacitance C = Q/U, combinations, stored energy, RC charge and discharge, time constant.
Magnets, B field, flux Φ, Laplace force, field of a coil, magnetisation curves.
Faraday's and Lenz's laws, cut flux, inductance L, energy ½LI², RL circuits.
Sine wave, angular frequency ω, frequency, period, RMS and peak values, phase shift.
Inductive and capacitive reactance, impedance, Ohm's law in AC, series and parallel.
Apparent S, active P and reactive Q power, power factor cos φ, correction.
Voltmeter, ammeter, ohmmeter, wattmeter, ranges, upstream and downstream connections, shunt.
In number order: each lesson builds on the previous ones. Units (lesson 1) and Ohm's law (lesson 4) are used everywhere; alternating current (lessons 12 to 14) requires capacitors and coils first.
Read the lesson, redo the worked example without looking at the solution, then work through a set of problems from the chapter. The summary at the end of the set shows the skills to work on again.
Yes, all 377 of them: each problem gives hints, then the full working, line by line, just like on the board.
For technical and vocational secondary school, and for adults going back to the basics (career change, electrician training). The first lessons require no prior knowledge.
No. The lessons, the formula sheet and the problems are freely available. A free account is only used to keep your favorites and progress on another device.