$\begin{array}{1 1} \text{maximum when the battery is connected across $1\;cm \times \large\frac{1}{2}$$\;cm$ faces} \\\text{maximum when the battery is connected across $10\;cm \times 1\;cm$ faces} \\ \text{maximum when the battery is connected across $10\;cm \times \large\frac{1}{2}\;$$cm$ faces} \\ \text{same irrespective of the three faces} \end{array} $