Question

A student is working on a circuitry project and wants to create an equivalent capacitance of $700F$. However, the student's only supply is a bag of $470F$ capacitors.
How can the student arrange any number of the $470F$ capacitors so that their equivalent capacitance is as close to $700F$ as possible?

• A. Two capacitors in parallel.
• B. Two capacitors in series.
• C. Three capacitors in parallel.
• D. Two capacitors in series connected to one other in parallel.
• E. Two capacitors in parallel connected to one other in series.

Answer 1

The correct option is D Two capacitors in series connected to one other in parallel.

Given : $C=470$ F

Equivalent capacitance of capacitors connected in series $C_s=\frac{C\times C}{C+C}=\frac{C}{2}=235$ F

$\therefore$ Equivalent capacitance of the whole circuit $C_{eq}=C+C_s=470+235=705$ F $\approx 700$ F