1. Dr. Hugh Blanton ENTC 3331

2. Charge Distributions

3. Dr. Blanton - ENTC 3331 - Charge Distribution 3 Electron Negative charge Greek for amber Discovered in 1897 by J.J. Thompson Elementary charge—1.6  10 -19 C.

4. Dr. Blanton - ENTC 3331 - Charge Distribution 4 Volume charge density: In general volume charge density is defined at a given point in space.

5. Dr. Blanton - ENTC 3331 - Charge Distribution 5 Rewriting the equation for volume charge density yields: Thus the total charge of Q in volume, V, is:

6. Dr. Blanton - ENTC 3331 - Charge Distribution 6 What is the total charge Q for a spherical shell 2cm  R  3cm with a charge distribution of x z y

7. Dr. Blanton - ENTC 3331 - Charge Distribution 7 (important: convert units cm  m before integration) spherical coordinates

8. Dr. Blanton - ENTC 3331 - Charge Distribution 8

9. Dr. Blanton - ENTC 3331 - Charge Distribution 9

10. Dr. Blanton - ENTC 3331 - Charge Distribution 10

11. Dr. Blanton - ENTC 3331 - Charge Distribution 11

12. Dr. Blanton - ENTC 3331 - Charge Distribution 12 Repulsion of charges and mobility in a conductor often depend upon surface charge. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

13. Dr. Blanton - ENTC 3331 - Charge Distribution 13 Surface charge density is: Thus the total charge of Q in volume, V, is:

14. Dr. Blanton - ENTC 3331 - Charge Distribution 14 Suppose you have a disk with a surface charge of: What is the total surface charge?

15. Dr. Blanton - ENTC 3331 - Charge Distribution 15

16. Dr. Blanton - ENTC 3331 - Charge Distribution 16 Find the surface area of the section shown. Using the spherical coordinate system,

17. Dr. Blanton - ENTC 3331 - Charge Distribution 17

18. Dr. Blanton - ENTC 3331 - Charge Distribution 18 Line Charge Density Thin wire ++++++++ 10 cm

19. Dr. Blanton - ENTC 3331 - Charge Distribution 19 What is the total charge, if the line density is: ++++++++ 10 cm

20. Dr. Blanton - ENTC 3331 - Charge Distribution 20

21. Dr. Blanton - ENTC 3331 - Charge Distribution 21 What is the total charge on the square plate?

22. Dr. Blanton - ENTC 3331 - Charge Distribution 22 Find the total charge for the disk. a Hint:

23. Dr. Blanton - ENTC 3331 - Charge Distribution 23 Find the total charge for the cube. 2 m x z y