An ideal capacitor of capacitance 0 .2 μ F is charged to a...

The energy stored in the capacitor is given by, ${U}_{c} = \dfrac{1}{2}C{V}^{2}$. The energy stored in the inductor is given by. ${U}_{L} = \dfrac{1}{2}L{I}^{2}$. In $LC$ circuit there is no loss of energy in the form of heat so, using energy conservation, ${U}_{ci} + {U}_{Li} = {U}_{cf} + {U}_{Lf}$

$⇒ \dfrac{1}{2} \times 0.2 \times {10}^{- 6} \times {10}^{2} + 0 = \dfrac{1}{2} \times 0.2 \times {10}^{- 6} \times {5}^{2} + \dfrac{1}{2} \times 0.5 \times {10}^{- 3}{I}^{2}$
$I = \sqrt{3} \times {10}^{- 1}A = 0 .17 A$