直列および並列のコンデンサ

In a series connection, each capacitor acquires an equal magnitude of charge Q. The plate connected to the battery's positive terminal develops a +Q charge, while the plate attached to the negative terminal is negatively charged at −Q. Charges are induced on the other plates so that the sum of charges on any pair of capacitor plates equals zero.

The potential drop on each capacitor in series varies as the ratio of the charge to its capacitance. The sum of potential drops across each capacitor equals the total battery voltage. Therefore, capacitors with lower capacitance experience larger potential differences than those with higher capacitance.

The reciprocal of equivalent capacitance in a series circuit equals the sum of reciprocals of individual capacitances: 1/Ceq = 1/C1 + 1/C2 + 1/C3. The resulting equivalent capacitance is always smaller than the smallest individual capacitance in the combination, reducing overall storage capacity.

In a parallel connection, the positive terminals of all capacitors connect to the battery's positive terminal, and negative terminals connect to the battery's negative terminal. This configuration ensures that the potential difference across each capacitor equals the battery voltage, remaining constant regardless of individual capacitance values.

The total charge stored by a parallel network equals the sum of charges stored in each individual capacitor. Since charge varies as the product of capacitance and potential difference, and voltage is constant across all capacitors, higher capacitance values store proportionally more charge.

The equivalent capacitance in a parallel circuit equals the sum of all individual capacitances: Ceq = C1 + C2 + C3. This additive relationship means the parallel combination resembles a single equivalent capacitor with higher total capacitance than any individual component in the network.

Series configurations produce an equivalent capacitance smaller than the smallest individual capacitor, reducing total storage capacity. Parallel configurations produce an equivalent capacitance equal to the sum of individual capacitances, increasing total storage capacity. The choice between configurations depends on whether reduced or increased capacitance is desired for the application.