Capacitors in Parallel
For capacitors connected between the same two nodes, voltage is common, total charge is the sum of branch charges, and equivalent capacitance is the direct sum.
Why this shows up in the exam
parallel banks · total charge from a battery · area-partition dielectric models
Learn the idea
Parallel capacitors share voltage and their capacitances add. Capacitors connected across the same two nodes experience the same potential difference; each stores charge according to its own capacitance.
🧠 Memory hook: Parallel: same V, add C.
Get this one clearly and it pays off every single time it shows up in the paper. 🎯
Formulas & facts to keep ready
- C_eq = sum C_i — parallel capacitors
- Q_i = C_i V — common branch voltage V
How to approach it
- 1Label the two terminal nodes
- 2Group every branch sharing both nodes
- 3Use common V to recover charges
Common slip-ups that cost marks
- •Assuming equal charge for unequal capacitors
- •Missing a branch that shares both nodes
- •Adding stored energies before finding actual voltage
🌟 That's the whole idea — you've got this. Try the practice set below; every question you attempt makes it stick a little harder.
Original chapter practice
Original questions for this chapter, not past-paper questions or an exact mapping to this individual concept.
Two point charges 1 microC and 2 microC are 1 m apart in vacuum. Take k = 9 x 10^9 SI. Find the force magnitude.
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