The equivalent capacitance of the combination of three capacitors, each of capacitance C shown in figure between points A and B is xC. The value of x is:

In the arrangement shown, both plates of capacitor C₃ are joined to point B. Hence, it does not act as a capacitor and is superfluous. Now, C₁ and C₂ are in parallel, hence

${\mathrm{C}}_{\mathrm{AB}}={\mathrm{C}}_1+{\mathrm{C}}_2=\mathrm{C}+\mathrm{C}=2\mathrm{C}$