Question

The resultant capacitance between the points $\text{A}$ and $\text{B}$ in figure

• A. $15\mu \text{F}$
• B. $30\mu \text{F}$
• C. $60\mu \text{F}$
• D. $45\mu \text{F}$

Answer 1

The correct option is A $15\mu \text{F}$

Let us redraw the circuit as shown below:


Here,

$C^{\prime }=(5+15+10)=30\mu \text{F}$

So, the equivalent capacitance,

$C_{AB}=\frac{\left(30\right)\left(30\right)}{\left(30\right)+\left(30\right)}=\frac{900}{60}=15\mu \text{F}$

Hence, option (a) is correct answer.

Why this question? This question will help the student to learn the art of redrawing a circuit.