Let 3 capacitors of capacitance $C_1,C_2,C_3$ be connected in series
The potential difference P is applied across the combination.
This sets up charger + or - q are the 2 plates of each capacitor .
The charge of +q is given to the left plate of capacitor $C_1$ during the charging process.
The charge $+q$ induces a charge $-q$ on the right plate of $-q$ on the left plate of $C_2$ etc .
(i) Charge is same in each capacitor
(ii)Potential is distributed in inverse proportion to capacitances
(i.e) $V=V_1+V_2+V_3$
But $V= \large\frac{q}{C},
V_1=
\large\frac{q}{C_1}, V_2=
\large\frac{q}{C_2}$ and $V_3=
\large\frac{q}{C_3}$
$\therefore \large\frac{q}{C}=\frac{q}{C_1}
+ \frac{q}{C_2}
+\frac{q}{C_3}$
where C is the equivalent capacitance or effective capacitance or net capacitance or total capacitance )
or $\large\frac{1}{c}= \frac{1}{C_1}
+\frac{1}{C_2}
+ \frac{1}{C_3}$
The reciprocal of the effective capacitance is the
sum of the reciprocals of the individuals capacitances .
