1. PHY 2049: Physics II Tutoring Center is open in room NPB 1215, M-F 12:00AM -4:00PM. It is free. Hopefully all homework problems have been solved. Please see me immediately after the class if there is still an issue. Exam I is on Friday May 30, 2008. It will be here in class during class time.

2. PHY 2049: Physics II An outline Capacitors, plate, coaxial, spherical.. Energy, Dielectric strength, Dielectric constant. Netweorks: Parallel and Series configuration.

3. PHY 2049: Physics II

4. Potential near a sheet charge

6. PHY 2049: Physics II

9. What is the capacitance of various familiar balls. C = 4 πε o R = 10 -10 R(m) F Basketball-it is an insulator Van de Graff top Earth (radius 6.4 X 10 6 m) C E = 0.71 mF

10. PHY 2049: Physics II Energy stored in a capacitor U = ½ CV 2 = Q 2 /2C = ½ QV Dielectric Strength (oops I burned/broke it) Capacitor Enhancement by inserting a dielectric: Replace ε o by κε o

11. PHY 2049: Physics II

14. Charging and discharging of capacitors. http://edugen.wiley.com/edugen/instructor/ main.uni

15. PHY 2049: Physics II 25.20

16. PHY 2049: Physics II Switch closed on left, capacitor C 1 is being charged We have c 2 = c 3 = 20 μF in parallel. The equivalent capacitor is then C eq = 40 μF. When the switch is thrown to right, the battery is disconnected, the charge is shared between the capacitors C 1 and C eq = 40. What is the charge on old C 2 and C 3 ? Is your answer 40 μC? What is your answer if C 2 = 10 μF and C 3 = 30 μF?

17. PHY 2049: Physics II All about capacitors Capacitance units Farad C = 4 π κε o R Energy stored dielectrics and strength Parallel and series elements in a network