Introduction into electronics

This is an introduction into the physics topic of electronics.

List of units and their relations

In the following section you can find the definitions of the most common symbols and their units encountered in the field of electronics.

Name	Mathematical Symbol	Unit Symbol	Unit Name	Dependencies	Description
Voltage	$U$ (sometimes $V$)	$V$	Volt	$U = R * I$ $\displaystyle U = \frac{P}{I}$ $\displaystyle U = \sqrt{P * R}$ $\displaystyle U = \frac{I}{G}$	A voltage describes a diffecence in electrical charges (such as electrons) between two areas or points. In this case you could also call this a potential difference. In more rare occasions a voltage can also describe the amount of electrical charge at a sp
Current	$I$	$A$	Ampère / Ampere	$\displaystyle I = \frac{U}{R}$ $\displaystyle I = \frac{P}{U}$ $\displaystyle I = \sqrt{\frac{P}{R}}$ $I = U * G$	A current describes the amount of electrical charge moved per time
Resistance	$R$	$\Omega$	Ohm	$\displaystyle R = \frac{U}{I}$ $\displaystyle R = \frac{U^2}{P}$ $\displaystyle R = \frac{P}{I^2}$ $\displaystyle R = \frac{1}{G}$	A resistance describes the charge difference between per moved electrical charge per time.
Conductance	$G$	$S$	Siemens	$\displaystyle G = \frac{1}{R}$ $\displaystyle G = \frac{I}{U}$	Conductance describes the amount of electrical charge moved per time per potential difference.
Power	$P$	$W$	Watt	$P = U * I$ $\displaystyle P = \frac{V^2}{R}$ $P = R * I^2$	Electrical power describes the amount of energy transfered / "used up" (converted to thermal energy) in a circuit.