The inductance of a closed-packed coil of 400 turns is 8 mH. A current of 5 mA is passed through it. The magnetic flux through each turn of the coil is

• A

  $\frac{1}{4\mathrm{\pi }}{\mathrm{\mu }}_0 \mathrm{Wb}$

• B

  $\frac{1}{2\mathrm{\pi }}{\mathrm{\mu }}_0 \mathrm{Wb}$

• C

  $\frac{1}{3\mathrm{\pi }}{\mathrm{\mu }}_0 \mathrm{Wb}$

• D

  $0.4{\mathrm{\mu }}_0 \mathrm{Wb}$