Question

In the arrangement of capacitors shown in the figure, if each capacitor is $9pF$, then the effective capacitance between the points $A$ and $B$ is

• A. 10 pF
• B. 15 pF
• C. 20 pF
• D. 5 pF

Answer 1

Answer: (B)

Effective capacitance between the points $A$ and $B$

$C_1$ and $C_3$ parallel
$\therefore C_1+C_3=18pF$
$18pF$ is in series with $C_2$
$\therefore \frac{18\times 9}{18+9}=6pF$
$6pF$ is in parallel with $9pF$
$\therefore 6+9=15pF$