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Question: Answered & Verified by Expert
A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A . The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4 \pi \times 10^{-7}$ SI units):
PhysicsMagnetic Effects of CurrentNEETNEET 2024
Options:
  • A 4.4 T
  • B 4.4 mT
  • C 44 T
  • D 44 mT
Solution:
1154 Upvotes Verified Answer
The correct answer is: 4.4 mT
The magnitude of magnetic field due to circular coil of $N$ turns is given by
$\begin{aligned}
& B_C=\frac{\mu_0 i N}{2 R} \\
& =\frac{4 \pi \times 10^{-7} \times 7 \times 100}{2 \times 0.1} \\
& =4.4 \times 10^{-3} \mathrm{~T} \\
& =4.4 \mathrm{mT}
\end{aligned}$

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