Question

Two identical capacitors are arranged in a circuit. What is the ratio of the equivalent capacitance of the circuit when the capacitors are in series to that when they are in parallel?

• A. $\frac{1}{4}$
• B. $\frac{1}{2}$
• C. 1
• D. 2
• E. 4

Answer 1

The correct option is A $\frac{1}{4}$

When the two identical capacitors are in series, the equivalent capacitance, $C_s=\frac{CC}{C+C}=C/2$

When the two identical capacitors are in parallel, the equivalent capacitance, $C_p=C+C=2C$

Thus, $\frac{C_s}{C_p}=\frac{C/2}{2C}=1/4$