In this paper, several methods based on Krylov methods are proposed to solve the singular linear systems from finite element method. Indeed, in the magnetostatic case, for A-formulation the system to solve is singular but it is auto-gauged by Krylov methods. However, due to the computation of residual vector all the methods (CG, MRTR, SQMR, MINRES) do not present the same behavior. Moreover, these methods are applied to eddy current problem. The numerical behavior are compared and analyzed.