Electric Field & Gauss's Law – AP Physics C E&M | ShowMeClass

Φ

Electric Field & Gauss's Law

AP Physics C: E&M · Unit 1: Electric Field

Learning Objectives

Apply Gauss's law to find E

Choose Gaussian surfaces by symmetry

Calculate E for sphere, cylinder, plane

Understand electric flux

Key Equations

Symmetry Guide

Spherical: point charge, sphere
Cylindrical: infinite line/wire
Planar: infinite sheet

Colors

E-field lines

Gaussian surface

Charge distribution

Gauss's LawFluxE-Field

E(r) =-

Phi =-

Q_enc =-

r =-

E(r) vs DISTANCE

Geometry

Q (uC) 5

R (m) 0.5

Gaussian r (m) 0.8

lambda (uC/m) 2

sigma (uC/m2) 3

Display

Gauss's Law Analysis

Quick Quiz▼

1. Inside a uniformly charged solid sphere, E(r) is proportional to:

1/r2 r 1/r constant

2. E inside a conducting spherical shell is:

Q/(4pi eps0 r2) Zero sigma/eps0 Q/(4pi eps0 R2)

3. E from an infinite plane of charge is:

sigma/(2 eps0), independent of distance sigma/eps0, depends on distance sigma*r/(2 eps0) Zero everywhere