Pyq- Electromagnetic Induction & Alternating Currents L-8

Question: A closely packed coil having 1000 turns has an average radius of $62.8 \mathrm{~cm}$. If current carried by the wire of the coil is $1 \mathrm{~A}$, the value of magnetic field produced at the centre of the coil will be (permeability of free space $\left.=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}\right)$ nearly (NEET-2022)#

A) $10^{-3} \mathrm{~T}$

B) $10^{-1} \mathrm{~T}$

C) $10^{-2} \mathrm{~T}$

D) $10^2 \mathrm{~T}$

Answer: $10^{-3} \mathrm{~T}$#

Explanation#

Magnetic field at the centre of coil

$B=\frac{\mu_0 N I}{2 R}$

On substituting the given values

$\Rightarrow B=\frac{4 \pi \times 10^{-7} \times 10^3}{2 \times 62.8 \times 10^{-2}}$

$=10^{-3} \mathrm{~T}$