Electrical basics

The quantities and laws every circuit obeys.

Voltage, current and resistanceThe three quantities every circuit is about.Ohm's lawThe relationship that links them, and how to use it.Power and energyWatts, joules and kilowatt-hours; P = E × I.AC, DC and waveformsSine, square and triangle; peak, peak-to-peak and RMS.Series and parallel circuitsHow resistors combine and where current and voltage divide.Kirchhoff's lawsCurrent in equals current out; voltages around a loop sum to zero.Units and metric prefixesFrom pico to giga, and converting without mistakes.Conductors and insulatorsWhy materials differ in how they carry current.