Three identical capacitors of capacitance ' $\mathrm{C}$ ' each are connected in series and this connection…
Three identical capacitors of capacitance ' $\mathrm{C}$ ' each are connected in series and this connection is connected in parallel with one more such identical capacitor. Then the capacitance of whole combination is
$3 \mathrm{C}$
$2 \mathrm{C}$
$\frac{4}{3} \mathrm{C}$
$\frac{3}{4} C$
Solution
The equivalent capacitance of three capacitances connected in series is
$\begin{aligned}
& \frac{1}{\mathrm{C}_{\text {eq }}}=\frac{1}{\mathrm{C}}+\frac{1}{\mathrm{C}}+\frac{1}{\mathrm{C}} \\
& \frac{1}{\mathrm{C}_{\text {eq }}}=\frac{3}{\mathrm{C}} \\
& \mathrm{C}_{\text {eq }}=\frac{\mathrm{C}}{3}
\end{aligned}$
This capacitance is connected in parallel with another capacitance.
$\begin{aligned}
& \Rightarrow C_{\text {total }}=\frac{C}{3}+C \\
& C_{\text {total }}=\frac{4 C}{3}
\end{aligned}$