where N is its number of turns in the toroid, \(\displaystyle R_1\) and \(\displaystyle R_2\) are the inner and outer radii of the toroid, h is the height of the toroid, and \(\displaystyle μ_0=4π×10^...where N is its number of turns in the toroid, \(\displaystyle R_1\) and \(\displaystyle R_2\) are the inner and outer radii of the toroid, h is the height of the toroid, and \(\displaystyle μ_0=4π×10^{−7}T⋅m/A\) is the permeability of free space. In the first time constant \(\displaystyle τ\), the current rises from zero to \(\displaystyle 0.632I_0\), and to 0.632 of the remainder in every subsequent time interval \(\displaystyle τ\).
