A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A . The magnitude of the magne

Question

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 $4 \pi 	imes 10^{-7}$ SI units)

Professor PC Thomas Classes · Answer

(c) : Number of turns in the coil, 
$N=100$ Radius of coil,
 $r=10 \mathrm{~cm}=0.1 \mathrm{~m}$ Current flowing in the coil, $I=7 \mathrm{~A}$ 
$B=\frac{4 \pi 	imes 10^{-7} 	imes 100 	imes 7}{2 	imes 0.1}=$
$\frac{4 	imes 3.14 	imes 10^{-7} 	imes 100 	imes 7}{2 	imes 0.1}$
$=43.96 	imes 10^{-4}=4.4 \mathrm{mT}$