---
title: "current"
type: concept
related: [Charged, Current]
source: https://www.jemoka.com/posts/kbhcurrent/
confidence: high
status: active
---

current is defined as the flow of positive charge. Specifically:
\begin{equation} I = \frac{\Delta Q}{\Delta t} \end{equation}
resistance of a wire (if ever you come across needing to calculate the resistance of the wire from scratch)
\begin{equation} R = \rho \frac{L}{A} \end{equation}
where, \(\rho\) is the material resistivity, \(L\) the length, and \(A\) the cross-sectional area.
you rarely need to do this!
