
Voltage, current and resistance
The voltage (V) between two points is the cost in energy necessary to move a unit of positive charge from the more negative point to the more positive point. It is measured in voltage. Current (I) is the flow of charge past a given point. It is measured in amperes. All elements in an electronics…

Root Mean Square (RMS)
Definition RMS is defined as the square root of the mean square. Why it’s useful An understanding of root mean square (RMS) is necessary when delving deeper into the science of voltage and frequency. RMS, in regards to electronics, gives us an easy way to do calculations with AC current. It lets us treat AC…

Capacitor impedance
Impedance vs resistance Impedance is resistance + reactance. Resistance is the opposition to flow of current, and entails power loss, usually in the form of heat. Reactance is the opposition to alternating current flow due to inductance or capacitance, and does not entail power loss. Capacitors and inductors store energy for a certain amount of…