Flashcards
Capacitors
Cards in this deck (9)
- 1Define Capacitance C=Q/Vthe charge stored per unit of p.d.
- 2How are capacitors constructed?Capacitors are constructed from two parallel metal plates separated by an insulator.
- 3Farad (unit of capacitance)A coulomb per volt.
1F = 1C/1V - 4Time constant t=CRTime for the charge to have decreased to 1/ℯ of its initial charge
- 5Energy stored in capacitorAs charge increases, repulsion between electrons on plate and new electrons increases. So more work must be done to increase charge stored.
- 6Work done in charging up capacitorW=1/2 QV
Sub Q=CV
W=1/2 CV^2
Sub V=Q/C
W=1/2 Q^2/C - 7Rules for capacitor connected in parallelC(total)=C1 + C2
p.d. across each is the same
total charge is =sum of individual charges
Q(total)=Q1+Q2 - 8Rules for capacitor connected in series1/C(total)=1/C1 +1/C2
total charge stored by each capacitor is the same
total p.d. V(total) is equal to sum of individual p.d.s V(total)=V1 +V2 - 9—
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- A-Level Physics (Capacitors) Flashcards on Capacitors, created by Shpat Agushi on 30/01/2016.
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- Shpat Agushi
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