A parallel plate capacitor of capacitance $2 \mathrm{~F}$ is charged to a potential $\mathrm{V}$, The energy stored in the capacitor is $E_{1}$. The capacitor is now connected to another uncharged identical capacitor in parallel combination. The energy stored in the combination is $\mathrm{E}_{2}$. The ratio $\mathrm{E}_{2} / \mathrm{E}_{1}$ is :