Question

Find the capacitance between $P$ and $O$ as shown in the figure. Each capacitor has capacitance $C$ :

• A. $2C$
• B. $3C$
• C. $8C$
• D. $6C$

Answer 1

Answer: (A)

$2C$

The four capacitors with capacitance C are in parallel in between P and A.

So equivalent capacitance of parallel combination $C_{PA}=C+C+C+C=4C$

Similarly, $C_{AO}=4C$

Now $C_{PA}$ and $C_{AO}$ are in series, so equivalent capacitance of series combination between P and O is $C_{PO}=\frac{C_{PA}{C}_{AO}}{C_{PA}+C_{AO}}=\frac{4C\times 4C}{4C+4C}=2C$