1. Chapter 25 Capacitance-II
In the last lecture:
we calculated the capacitance C of a system of two isolated conductors.
We also calculated the capacitance for some simple geometries.
In this chapter we will cover the following topics:
-Methods of connecting capacitors (in series , in parallel) Equivalent capacitance Energy stored in a capacitor Behavior of an insulator (a.k.a. dielectric) when placed in the electric field created in the space between the plates of a capacitor Gauss’ law in the presence of dielectrics.
(25 - 1)

2. HITT
An electron moves from point i to point f, in the direction of a uniform electric field. During this displacement: i j
A. the work done by the field is positive and the potential energy of the electron-field system increases
B. the work done by the field is negative and the potential energy of the electron-field system increases
C. the work done by the field is positive and the potential energy of the electron-field system decreases
D. the work done by the field is negative and the potential energy of the electron-field system decreases
E. the work done by the field is positive and the potential energy of the electron-field system does not change b

3. (25 - 9)

4. ( )

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6. ( )

7. - +
dq' q'
-q' V' q' q V' V
Charge
Voltage O A B
( )

8. - + q -q d A
( )

9. q -q q'
-q' V V'
( )

10. q -q q'
-q' V V'
( )

11. q
conductor
dielectric
( )

12. ( )

13. ( )

14. S
( )

15. ( )

16. HITT
A parallel-plate capacitor has a plate area of 0.2m2 and a plate separation of 0.1 mm. To obtain an electric field of 2.0 x 106 V/m between the plates, the magnitude of the charge on each plate should be:
A. 8.9 x 10-7 C B. 1.8 x 10-6 C C. 3.5 x 10-6 C D. 7.1 x 10-6 C E. 1.4 x 10-5 C c