Two windings are wound on a toroid core. The core is made of silicon steel and has a square cross$-$section. The primary winding current is $0\mathrm{.}25$ A and the secondary winding current is $0\mathrm{.}55$ A$.$

d$)$ Determine the flux density at the core mean radius

e$)$ Assuming the flux density is constant throughout the core, determine the flux in the core

f$)$ Determine the relative permeability of the core.