Question

A network of four $20$ $\mu F$ capacitors is connected to a $600V$ supply as shown in the figure.
The equivalent capacitance of the network is:

• A. $30.26$ $\mu F$
• B. $20$ $\mu F$
• C. $26.67$ $\mu F$
• D. $10$ $\mu F$

Answer 1

The correct option is C $26.67$ $\mu F$

From the figure, $C_1,C_2,C_3$ are connected in seris
$\therefore \frac{1}{C_s}=\frac{1}{C_1}+\frac{1}{C_2}+\frac{1}{C_3}=\frac{1}{20}+\frac{1}{20}+\frac{1}{20}=\frac{3}{20}\mu For{C}_s=\frac{20}{3}\mu F$
Now $C_S$ is in parallel with $C_4$
$\therefore$ equivalent capacitance
$C_{eq}=C_s+C_4=\frac{20}{3}+20=\frac{80}{3}=26.67\mu F$