Question

Find the equivalent capacitance across $A\&B$

• A. $\frac{28}{3}\mu F$
• B. $\frac{15}{2}\mu F$
• C. $15\mu F$
• D. none

Answer 1

Answer: (B)

It is clear $\frac{C_1}{C_3}=\frac{7}{2}$ and $\frac{C_2}{C_4}=\frac{7}{2}$
So balanced W.B., we can remove $13\mu F$

$\frac{1}{7}+\frac{1}{35}=\frac{6}{35}$
$\frac{1}{10}+\frac{1}{2}=\frac{1+5}{10}=\frac{6}{10}$
$C_{eq}=\frac{35}{6}+\frac{10}{6}=\frac{45}{6}=\frac{15}{2}$