A toroid has an iron core with an internal magnetic field of $10\mathrm{\pi mT}$, when the current in the winding of 1500 turns per meter is $10 \mathrm{A}$. Deternine the field due to magnetization $\left({\mathrm{\mu }}_0=4\mathrm{\pi }\times {10}^{-7}{\mathrm{Hm}}^{-1}\right)$

• Correct answer
  A

  $\left(4\mathrm{\pi }\right)\mathrm{mT}$
• B

  $\left(10\mathrm{\pi }\right)\mathrm{mT}$
• C

  $\left(\frac{8}{\mathrm{\pi }}\right)\mathrm{mT}$
• D

  $\left(\frac{\mathrm{\pi }}{4}\right)\mathrm{mT}$

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