Question

A toroid has a core(non-ferromagnetic) of inner radius $25$cm and outer radius $26$cm, around which $3500$ turns of a wire are wound. If the current in the wire is $11$A, the magnetic field inside the core of the toroid is?

Answer 1

$r_1=0.25m,r_1=0.26m,N=3500,I=11A$

Let $B=\frac{{\mu }_{0}NI}{I},$

${\mu }_0$=Permeability of free space = $4\pi \times {10}^{-7}Tm{A}^{-1}$

$Length,L=2\pi \left(\frac{r_1+r_2}{2}\right)$

$=\pi (0.25+0.26)$

$=0.51\pi$

$B=\frac{4\pi \times {10}^{=7}\times 3500\times 11}{0.51\pi }=3.0\times {10}^{-2}T$