1. Example: use Gauss’ Law to calculate the electric field due to a long line of charge, with linear charge density .
This is easy using Gauss’ Law (remember what a pain it was in the previous chapter). Study the examples in this lecture and others in your text!
To be worked at the blackboard in lecture.

2. Example: use Gauss’ Law to calculate the electric field due to a long line of charge, with linear charge density .
Line is looooooong. E 
>0

3. E r dA
Looking down the line.

4. dA E 
>0 r L

5. dA E 
>0 r L

6. Same as outside a solid cylinder!
>0
For positive :
Same as outside a solid cylinder!
In general: