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| Combination of Capacitors |
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| In many electrical circuits, capacitors are to be grouped suitably to obtain the desired capacitance. The two most common modes are: |
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| 1. Capacitors in series |
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| 2. Capacitors in parallel |
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| Capacitors in Series |
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| If +Q units of charge are given to left plates of C1, then by induction |
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| -Q charge appears on the right plate. +Q appears on the left plate of capacitor C2 and so on. Thus, same charge appears on each capacitor. |
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| The potential difference across each capacitor however is different. Therefore, |
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| V = V1 + V2 + V3 |
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| On substituting, |
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| OR |
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| where CS is the effective capacitance, when capacitors are connected in series. |
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| This implies that when the capacitors are connected in series, the reciprocal of the equivalent capacitance equals to the reciprocals of the individual capacitance. |
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| Capacitors in Parallel |
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| Here, the potential difference across each capacitor is the same but charges are different. Therefore, |
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| Q = Q1 + Q2 + Q3 |
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| CPV = C1 V + C2V + C3V |
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| CP = C1 + C2 + C3 |
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| where Cp is the effective capacitance, when capacitors are connected in parallel. |
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| This implies that when the capacitors are connected in parallel, the equivalent capacitance equals the sum of the individual capacitance. |
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