Physics II - B07
TABLE OF CONTENTS
Revision
\[V_1 = V2\] \[\frac{q_1}{R_1} = \frac{q_2}{R_2}\] \[\frac{\sigma_1}{\sigma_2} = \frac{q_1}{q_2}.\frac{R_2^2}{R_1^2}\]
Capacitance (Điện dung)
- C doesn’t depend on Q and $\Delta V$
Parallel Plate Capacitor(Tụ điện)
Capacitance of a Cylindrical Capacitor
Capacitance of a Spherical Capacitor
- $a \approx b: C \approx \frac{A.\epsilon_0}{d}$
- $b \to \infty: C \approx 4\pi\epsilon_0a$
Capacitors in Parallel
- $Q_{total} = Q_1 + Q2 = (C_1 + C_2).\Delta V$
- $C_{total} = C_1 + C_2$
- $\Delta V_1 = \Delta V_2 = \Delta V$
Capacitors in Series
- $Q_1 = Q_2 = Q$
- $\Delta V_{total} = \Delta V_1 + \Delta V_2$
- $\frac{1}{C} = \frac{1}{C_1}+ \frac{1}{C_2}$
Energy Stored in a Capacitor
Notes
- Vacuum: chân không
- $F = -\frac{dU}{dx}$
Other references