Tiga kapasitor c1,c2, dan c3 disusun seri ternyata kapasitas gabungannya 4 mf besar kapasitas c1 dan c3 masing 9 mf dan 18 mf.Hitunglah kapasitas 2

c1 = 9 mf
c3 = 18 mf
Cs = 4 mf
c2?

penyelesaian:
1/Cs = 1/c1 + 1/c2 + 1/c3

1/c2 = 1/Cs - 1/c1 - 1/c3

1/c2 = 1/4 - 1/9 - 1/18

1/c2 = 9/36 - 4/36 - 2/36

1/c2 = ( 9 - 4 - 2 ) /36

1/c2 = 3/36

c2 = 36/3

c2 = 12 mf