Let three capacitors
C1 , C2 and C3 be connected in series as shown.
The capacitor plates are named A,B,C,D,E and
F.
When a battery is connected to the series combination,
the negative terminal of the battery supplies a
–ve charge to plate F. Simultaneously, the positive terminal of the
battery sucks negative charge from plate A and therefore creating a +ve charge
on plate A. Thus, charge is conserved.So now plate A has a +ve charge and plate F has a –ve
charge as shown.
Positive charge on plate A attracts electrons of the BC plate combination towards plate B. Therefore, a –ve charge and a +ve charge appears on plate B and plate C respectively as shown. The BC plate combination which is isolated from everything else remains neutral as a whole and only redistribution of charge takes place.
Similarly, electrons of the DE plate combination drift
towards plate D , thus giving plate D a –ve charge and plate E a +ve
charge as shown. Again, the DE plate combination
as a whole remains neutral.
The above process continues till capacitors get fully
charged.
You may have observed that any charge sent/sucked by
the battery to /from the end plates i.e Plates A and F will induce an equal amount of charge in all
the plates in between i.e in Plates B,C,D and E .
Therefore, in series
combination of capacitors, each capacitor has equal charge for any value of
capacitances.
As Q=CV for a capacitor
To summarise
:-
- All capacitors in series store equal charge for any value of capacitances.
- Equivalent capacitance value is smaller than all the individual capacitance values.
- Equivalent
capacitance value is given by
- As
Q=same for all the capacitors connected in series
therefore,
