When induced emf in inductor coil is $50\mathrm{\%}$ of its maximum value then stored energy in inductor coil in the given circuit will be

• Correct answer
  A

  $2.5\mathrm{ }\mathrm{m}\mathrm{J}$
• B

  $5\mathrm{ }\mathrm{m}\mathrm{J}$
• C

  $15\mathrm{ }\mathrm{m}\mathrm{J}$
• D

  $20\mathrm{ }\mathrm{m}\mathrm{J}$

Hence, the correct answer is option: 'A'.