Question

A toroid of circular cross section of radius 0.05 m has 2000 windings and a self inductance of 0.04 H. What is (a) the current through the windings when the energy in its magnetic field is 2 × 10^-6 J (b) the central radius of the toroid ?

Answer 1

Data : r = 0.05 m, N = 2000, L = 0.04 H,

U_m = 2 × 10^-6 J, μ₀ = 4π × 10^-7 H/m

(a) U_m = \(\cfrac12\)LI²

Therefore, the current in the windings,

Therefore, the central radius of the toroid,