Question

The equivalent capacitance of the combination shown in the figure is

• A. $C$
• B. $2C$
• C. $C/2$
• D. $C/4$

Answer 1

The correct option is B $2C$

A connecting wire is connected across the third or the right-most capacitor. It is of no use, as the potential difference across it is zero. Thus, the circuit gets reduced to two capacitors in parallel.

Hence, equivalent capacitance will be

$C_{eq}=C+C=2C$

Therefore, option $\left(b\right)$ is correct.

Key Concept - If the potential difference across a capacitor is zero, it can be replaced with a plane conducting wire.