Elec Class
learn electricity hands-on
For teachers and trainers
Free, no account and nothing to install: project a hands-on demo, give worked problems for class or homework, prepare a measurement session. 377 problems across 15 chapters of basic electricity.
A chapter, a level, a number: the list of links is ready to copy.
1I choose the chapter
2The level
3The number of problems
4The set to assign
Ohm's law10 problems
Four ways to use it, and the course covered chapter by chapter.
| Chapter | Topics | Problems | Levels |
|---|---|---|---|
| 1. Electrical units and conversions | SI system, prefixes, scientific notation, significant figures, IEC symbols, reading instruments. | 15 | 1 to 2 |
| 2. Electrostatics and Coulomb's law | Atom, charges, conductors and insulators, Coulomb's law, electric field. | 7 | 1 to 3 |
| 3. Voltage and current | Potential, p.d., current direction, quantity of electricity Q = I·t, current density, generation and distribution. | 22 | 1 to 3 |
| 4. Ohm's law | U = R·I, Pouillet's law, temperature effect, E12 series. | 61 | 1 to 4 |
| 5. Electric power | P = U·I, W = P·t, Joule heating, joule and kWh, efficiency of a power chain. | 34 | 1 to 4 |
| 6. Series and parallel circuits | Series, parallel, mixed, equivalent resistance, line voltage drop. | 71 | 1 to 4 |
| 7. EMF and internal resistance | EMF E and internal resistance r, back-EMF E' and r', generalised Ohm's law, U = f(I) characteristic. | 36 | 1 to 4 |
| 8. Kirchhoff's current and voltage laws | Loop rule, junction rule, circuits with several sources. | 12 | 1 to 5 |
| 9. Capacitors and RC circuits | Capacitance C = Q/U, combinations, stored energy, RC charge and discharge, time constant. | 17 | 1 to 4 |
| 10. Magnetism and magnetic force (F = BIL) | Magnets, B field, flux Φ, Laplace force, field of a coil, magnetisation curves. | 16 | 1 to 4 |
| 11. Electromagnetic induction | Faraday's and Lenz's laws, cut flux, inductance L, energy ½LI², RL circuits. | 20 | 1 to 5 |
| 12. Alternating current | Sine wave, angular frequency ω, frequency, period, RMS and peak values, phase shift. | 15 | 1 to 4 |
| 13. RLC circuits and impedance | Inductive and capacitive reactance, impedance, Ohm's law in AC, series and parallel. | 21 | 1 to 5 |
| 14. Power factor and AC power | Apparent S, active P and reactive Q power, power factor cos φ, correction. | 15 | 1 to 5 |
| 15. Voltmeter and ammeter | Voltmeter, ammeter, ohmmeter, wattmeter, ranges, upstream and downstream connections, shunt. | 15 | 1 to 4 |
Nothing to install, nothing to create: a lesson takes five minutes to prepare.
Open the lesson: definition, formulas and worked example, ready to project.
Change a value in the calculator or build the circuit in the lab.
Build a set above and paste the links into the class platform.
At the end of a set, each student sees a summary by skill and what to go over again.
ExampleA 50-minute period on Ohm's law: 10 min of projected lesson, 25 min of level 1 and 2 problems, 15 min of measurements in the lab.
Yes: the lessons, the problems, the lab and the learning paths are free, for students and teachers alike.
No. Everything works without an account. A free account is only used to keep favorites and progress from one device to another.
Without an account, progress stays in the student's browser. Audience measurement is anonymous and sets no advertising cookie; the details are on the Privacy page.
Technical and vocational secondary school, electrician training and adult education. Each problem has a level from 1 to 5: the first ones require no prior knowledge.
A recent browser is enough, on a computer, tablet or Chromebook. The lessons and problems remain readable on a phone; the lab is more comfortable on a large screen.
Many problems are parametric: the values change with every draw, so two students don't get the same results.
Through the contact form. Reports from teachers are handled first.
The pages to keep at hand during class.