કુલ કેપેસીટન્સ \( = \frac{{2{\varepsilon _0}A}}{d}\,\,\,\,\,\therefore \,\) સંગ્રહાયેલી ઉર્જા \( = \frac{1}{2}\left( {\frac{{2{\varepsilon _0}A}}{d}} \right)\,{V^2}\)
\( = \frac{{8.86 \times {{10}^{ - 12}} \times 50 \times {{10}^{ - 4}} \times {{12}^2}}}{{3 \times {{10}^{ - 3}}}} = 2.1 \times {10^{ - 9}}J\)