in Physics

Capacitors in Series

  • The charge is always the same for capacitors in series.
  • Turn series capacitors into an equivalent capacitor like so:

screen-shot-2016-11-13-at-15-22-52

  • These are eg. C1, C2, and C3
  • Changing them into CEquivalent like so:

screen-shot-2016-11-13-at-15-23-19

1 / CEquiv = 1/C1 + 1/C2 + 1/C3 + ….



 

  • The sum of the voltages across capacitors in series will equal the voltage of the battery

To calculate the voltage of capacitors:

Voltage across the capacitor (V) = Charge stored on a capacitor (Q) / Capacitance (C)

V = Q / C

  • Q will remain constant in a series
  • C depends on the capacitor

  • For the above image: Q/C1 + Q/C2 + Q/C3 = V (battery)
  • Therefore: Q (1/C1 + 1/C2 + 1/C3) = V (battery)
  • Finally we can deduce

1/C1 + 1/C2 + 1/C3 = V/Q = 1 / CEquivalent

 



Recommended Reading for Physics