Question

What is the equivalent capacitance of the system of capacitors between $A\text{\&}B$?

• A. $\frac{7}{6}C$
• B. $1.6C$
• C. $C$
• D. None

Answer 1

Answer: (B)

$1.6C$

The capacitors in the right hand square are in series. So they can be replaced by an equivalent capacitor of capacitance of:
$1/(1/C+1/C)=C/2$
The next step is to replace C and C/2 by a capacitor having an equivalent capacitance of C and C/2 in parallel.
$C+C/2=3C/2$
Then, C and 3C/2 are in series. So, they can be replaced by a capacitor having an equivalent capacitance of
$1/(1/C+2/3C)=3C/5$
Then since in parallel they can be replaced by an equivalent capacitance of $C+3C/5=8C/5=1.6C$
So the equivalent capacitance is 1.6C.