Q- A circular torus has inner radius R₁ = 30 cm, outer radius R₂ = 50 cm, and N = 710 turns wound uniformly around it. The current in the windings is I = 3 A.

(a) Calculate the magnitude of the magnetic field B, inside the torus, in the symmetrical plane along the inner and outer diameter, at the following distances from the axis of symmetry: r₁ = 35 cm, and r₂ = 40 cm. 

(b) Calculate the magnitude of the magnetic field B, outside the torus, in the symmetrical plane along the inner and outer diameter, at the following distances from the axis of symmetry: r₃ = 0 and r₄ = 60 cm. 

Solution: