Outline

• Applications of Gauss’s Law- The single Fixed Charge- Field of a sphere of charge- Field of a spherical shell- A Line of Charge• Conductors and Insulators• The electric field of a conductor• The field in the cavity of a conductor;

Faraday’s Cage

Gauss’s Law

The total flux of electric field out of any closed surface is equal to the charge contained inside the surface divided by .0

S

enclosedQSdE

0

Electric field of a ball of charge

30

20

4

1

4

1

R

rQERr

r

QERr

Q

Electric field outside of a charged sphere is exactly the same as the electric field produced by a point charge, located at the center of the sphere, with charge equal to the total charge on the sphere.

Electric field of a spherical shell

Q

The field outside the shell is like that of a point charge, while the field everywhere inside the shell is zero.

Electric field of a line of charge

rE

02

Conductors and insulators

Charges reside at the surface of the conductor

Conductor

E=0+

+ ++

+

+++

++

+++

+

+

First exam Tuesday, February 17

105 Heldenfels

Sections 807 and 808 start at 7 pm

Sections 809 and 523 start at 8:10 pm

No calculators and cell phones

BRING YOUR STUDENT ID!

What is included?

Chapters 1-4

Have a great day!Be prepared for the test!