Physics - Capacitor Question with Solution | TestHub

Consider the following diagram with nodes Q having same potential due to the symmetry of the circuit:
Taking the similar nodes together the equivalent diagram can be drawn as:
Therefore, the eqiuvalent capacitance between $\mathrm{AQ}=3C+2C+C=6C$ the equivalent capacitance between $\mathrm{QB}=3C+2C+C=6C$ Now, for equivalent capacitance between $AB$ $\begin{array}{rl}& \frac{1}{C_{\mathrm{AB}}}=\frac{1}{6C}+\frac{1}{6C}=\frac{1}{3C}\\ & \therefore C_{\mathrm{AB}}=3C\end{array}$