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 $13\, \mu F$

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