Magnetic complex impedance (SI unit : S) is determined by: Z M = F Φ Φ ˙ ˙ = z M e j ϕ ϕ where z M is the modulus of Z M and ϕ ϕ is its phase. The argument of a complex magnetic impedance is equal to the difference of the phases of the magnetic tension and magnetic current. Complex magnetic impedance can be presented in following form: Z M = z M e j ϕ ϕ = z M cos ⁡ ⁡ ϕ ϕ + j z M sin ⁡ ⁡ ϕ ϕ = r M + j x M where r M = z M cos ⁡ ⁡ ϕ ϕ is the real part of the complex magnetic impedance, called the effective magnetic resistance, and x M = z M sin ⁡ ⁡ ϕ ϕ is the imaginary part of the complex magnetic impedance, called the reactive magnetic resistance. The magnetic impedance is equal to z M = r M 2 + x M 2 , ϕ ϕ = arctan ⁡ ⁡ x M r M