Question

Find the capacitance between $\text{P}$ and $\text{O}$, if each capacitor has capacitance $C$.

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

Answer 1

The correct option is A $2C$

By symmetry, clearly $\text{A, B, C, D}$ are equipotential points.

$\Rightarrow V_A=V_B=V_C=V_D$

Redrawing the circuit,


So, the equivalent capacitance across $\text{P}$ and $\text{O}$,

$\Rightarrow C_{eq}=\frac{\left(4C\right)\left(4C\right)}{\left(4C\right)+\left(4C\right)}$

$\Rightarrow C_{eq}=2C$

Hence, option (a) is correct answer.

Why this Question : This question will help the students to learn the approch of redrawing a complex circuit by analysing the equipotential points in a circuit.