From 9eb8ed33d42bb5418897b6e862cd45ae87930b85 Mon Sep 17 00:00:00 2001 From: arc Date: Tue, 6 Jan 2026 08:17:37 -0700 Subject: [PATCH] vault backup: 2026-01-06 08:17:37 --- education/physics/PHYS2220/Electric Charge.md | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/education/physics/PHYS2220/Electric Charge.md b/education/physics/PHYS2220/Electric Charge.md index 27464fe..15a4541 100644 --- a/education/physics/PHYS2220/Electric Charge.md +++ b/education/physics/PHYS2220/Electric Charge.md @@ -31,5 +31,6 @@ An electric dipole consists of two point charges of equal magnitude but opposite # Continuous Charge Distributions It's largely impossible to sum the electric field from every particle in a piece of matter, so the approximation is made that the charge is spread continuously over the distribution. -- If the charge distribution extends throughout a 3d volume, we describe it in terms of the **volume charge density** $\rho$, with units of $\frac{C}{m^3}$. -- For charge distributions spread over surf \ No newline at end of file +- If the charge distribution extends throughout a *3d volume*, we describe it in terms of the **volume charge density** $\rho$, with units of $\frac{C}{m^3}$. +- For charge distributions spread over *surfaces*, we use **surface charge density** $\sigma$ ($\frac{C}{m^2}$). +- For charge distributions spread over *lines*, we use **line charge density** $\lambda$ ($\frac{C}{m}$). \ No newline at end of file