a
\(\mathrm{V}_{\mathrm{C}}-\frac{\mathrm{q}_{\text {net }}}{\mathrm{C}_{\text {net }}}=\frac{\mathrm{CV}+2 \mathrm{CV}}{2 \mathrm{C}}\)

\(\mathrm{V}_{\mathrm{C}}=\frac{3 \mathrm{~V}}{2}\)

Loss of energy

\(=\frac{1}{2} \mathrm{CV}^2+\frac{1}{2} \mathrm{C}(2 \mathrm{~V})^2-\frac{1}{2} 2 \mathrm{C}\left(\frac{3 \mathrm{~V}}{2}\right)^2\)

\(=\left(\frac{\mathrm{CV}^2}{4}\right)\)