1. Ye olde capacitor 8.3 Instructor Course
Presentation slide for courses, classes, lectures et al.
Ye olde capacitor 8.3
Instructor Course

2. Today & Beyond Quiz Material on Capacitors not in the unit.
Complete the unit (9)
SPRING BREAK
RETURN
Monday – Begin Unit on Magnetism. (Bring to class)
Wednesday – EXAMINATION #2 / Bring in units 4-9 / Lab Reports Due.
Friday – Continue magnetism unit.

3. What is the current through the 4- resistor in this circuit?
a) A
b) A
c) 1.0 A
d) 1.5 A
e) 4.5 A
Text Answer

4. What's Happening?
DIELECTRIC

5. Polar Materials (Water)

6. Apply an Electric Field
Some LOCAL ordering Larger Scale Ordering

7. Adding things up..
Net effect REDUCES the field

8. Non-Polar Material

9. APPLICATION OF GAUSS’ LAW

10. We can measure the C of a capacitor (later)
C0 = Vacuum or air Value
C = With dielectric in place
C=kC0

13. Dielectric Breakdown!

14. Recall the experiment –
Voltage across C seemed to drop rather than stay stable.
You were given a second capacitor and it held it’s value.
What’s going on???
meters have resistors of 1-10MW

15. Let’s talk about this…

16. 20.13 RC Circuits
Capacitor charging
time constant

17. Capacitor discharging
20.13 RC Circuits
Capacitor discharging
time constant

18. Stored Energy
Charge the Capacitor by moving Dq charge from + to – side.
Work = Dq Ed= Dq(V/d)d=DqV

19. DW=DqV=Sum of strips DV

20. Energy Density

21. A Thunker
Find the equivalent capacitance between points a and b in the combination of capacitors shown in the figure.
V(ab) same across each

22. Let’s Finish the Unit