Question

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

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

Answer 1

The correct option is B $15$pF

capacitor in parallel

$c_3+c_1=18pf=c^{\prime }$

and in series

$\frac{1}{c}=\frac{1}{c^{\prime }}+\frac{1}{c_2}$

$\frac{1}{18}+\frac{1}{9}$

= $\frac{1}{6}$

$c^{\prime }=6pf$

so equivalent = ( 9 + 6 ) pf

$=15pf$