Capacitors in Series and Parallel
Capacitors in Series and Parallel
- Decide what is the same before recalling a formula: charge in series, or p.d. in parallel.
The two connection patterns
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Series
Every capacitor stores the same charge. The individual p.d.s add. Reciprocal capacitances add.
Parallel
Every branch has the same p.d. The individual charges add. Capacitances add.
Common mistake
Capacitor rules are opposite to resistor rules. A series combination must be smaller than its smallest capacitor.
Derive the two rules
Recent mark schemes award the physical rule before the algebra (9702/42/M/J/24 Q6(a)).
Worked example
Parallel: same p.d.
Result: the capacitances add.
Worked example
Series: same charge
Answer