The spherical capacitor(球电容器 E= 4π6。r1 △U= gdr ,4rr 4π6。 R Ra C=9 RARB △U =4rR。-R4 when Rg-→oo C=4π6R
The spherical capacitor（球电容器） RA RB B A A B o R R R R U q C 4
Energy in capacitor dq a If we want move dq from the plate with negative charge to the positive one,the work needed is: duuldid
Energy in capacitor dq -q +q If we want move dq from the plate with negative charge to the positive one, the work needed is:
5小12g呈 Because Q=CU,the result can also be written as: 号r 2
Because Q=CU, the result can also be written as:
Capacitors in parallel g=CV,4=C,U,…UC宁c宁c= 9=q+9+…+qn=(C+C2+…Cn)U The equivalent capacitance =号=G+C++C
Capacitors in parallel , , U C1 C2 C3 q1 C1 U q2 C2 U q q1 q2 qn C1 C2 Cn U The equivalent capacitance
Capacitor in series 号培共 U-+,…U,-G++ The equivalent 1J11.1 一十 capacitance
Capacitor in series C1 C2 Cn U The equivalent capacitance