Electrical concepts, clearly explained
From charge and Ohm’s law to protective earthing and EV high-voltage systems. Each concept includes a definition, three levels of explanation, formulas, solved examples, applications, measurement notes, mistakes and safety guidance.
Reactance
Reactance is the opposition that inductors and capacitors offer to alternating current. It depends on frequency and shifts curre...
Impedance
Impedance is the total opposition to alternating current, combining resistance and reactance. It sets both the current magnitude...
Electrical Circuit
An electrical circuit is a closed path that lets current flow from a source through a load and back. Learn its parts, series and...
Circuit Diagram
Circuit diagrams use standard symbols to show how components connect. Reading one means following nodes, paths and reference des...
Short Circuit
A short circuit is an unintended low-resistance path that lets a large current bypass the load. Understanding fault current is t...
Open Circuit
An open circuit is a broken path where current cannot flow. Voltage may still be present, which makes open-circuit faults easy t...
Electrical Power
Electrical power is the rate at which energy is transferred. Learn the three power formulas, when to use each, and how power rel...
Electrical Energy
Electrical energy is power multiplied by time. Learn watt-hours and kilowatt-hours, battery capacity, and how to calculate runni...
Power Factor
Power factor is the ratio of active power to apparent power. A low power factor means more current for the same useful work, so...
Three-Phase Power
Three-phase power delivers constant power with less conductor material. Learn the √3 formulas, star and delta connections and ba...
AC Power
AC power has three components: active, reactive and apparent. Learn the power triangle, instantaneous power and how to calculate...
Magnetism
Magnetism is the force field produced by moving charges and permanent magnets. It is the link between current, force and induced...