Question

The effective capacitance between $\text{A}$ and $\text{B}$ is

• A. $\frac{C}{4}$
• B. $\frac{3C}{4}$
• C. $\frac{C}{3}$
• D. $\frac{4C}{3}$

Answer 1

The correct option is D $\frac{4C}{3}$

The first three capacitors are in series, and this combination is in parallel to the fourth one.



The equivalent capacitance of the first three capacitors is given by

$\frac{1}{C_{series}}=\frac{1}{C}+\frac{1}{C}+\frac{1}{C}=\frac{3}{C}$

$\Rightarrow C_{series}=\frac{C}{3}$

Equivalent capacitance across $\text{AB}$ will be

$C_{eq}=C_{series}+C=\frac{C}{3}+C=\frac{4C}{3}$

Hence, option $\left(d\right)$ is correct.