Summary: Physical Fundamentals
| Physical quantity | Symbol | Unit name | Unit symbol |
|---|---|---|---|
| Charge | \(Q\) | coulomb | \(1\,\mathrm{C} = 1\,\mathrm{A} \cdot \mathrm{s}\) |
| Potential | \(\varphi\) | volt | \(\mathrm{V} = \dfrac{\mathrm{Nm}}{\mathrm{As}}\) |
| Voltage | \(U\) | volt | \(\mathrm{V} = \dfrac{\mathrm{Nm}}{\mathrm{As}}\) |
| Current | \(I\) | ampere | \(\mathrm{A}\) |
| Conductance | \(G\) | siemens | \(1\,\mathrm{S} = 1\,\mathrm{A}/\mathrm{V}\) |
| Resistance | \(R\) | ohm | \(1\,\Omega = 1\,\mathrm{V}/\mathrm{A}\) |
\[
\begin{gathered}
I(t) = \frac{dQ(t)}{dt} \\[8pt]
Q(t) = Q_0 + \int I(t)\,dt \\[8pt]
U = R \cdot I \\[4pt]
I = G \cdot U \\[8pt]
G = \kappa \cdot \frac{A}{l} \\[8pt]
R = \frac{1}{G} = \frac{1}{\kappa} \cdot \frac{l}{A} \\[8pt]
P(t) = \frac{dW(t)}{dt} \\[8pt]
W(t) = W_0 + \int P(t)\,dt
\end{gathered}
\]