C1 C2の合成
10 * 30 / 10 + 30 = 7.5 [μF]
Q = CV より
Q = 7.5 * 12
Q = 90[C]
1 Q = CV
90 = 10 * V
V = 9 [V]
2 12 - 9 = 3 [V]
Q = CV
Q = 30 [μF] * 3
Q = 90 [μC]
3 Q = CV
Q = 10[μF] * 12
Q = 120[μC]
よって正解は4
C1 C2の合成
10 * 30 / 10 + 30 = 7.5 [μF]
Q = CV より
Q = 7.5 * 12
Q = 90[C]
1 Q = CV
90 = 10 * V
V = 9 [V]
2 12 - 9 = 3 [V]
Q = CV
Q = 30 [μF] * 3
Q = 90 [μC]
3 Q = CV
Q = 10[μF] * 12
Q = 120[μC]
よって正解は4