Abstract
In this study, we propose to introduce and apply an accurate numerical procedure to solve the mathematical model of fractional order, which describes the electrical circuits composed of resistors and inductors (RL) driven by a voltage of the current source. Our research is based on the spectral collocation method, which utilizes the advantageous characteristics of the third-order Chebyshev polynomials. Some convergence analysis and error theorems are presented. The proposed research concludes by comparing the approximate solutions obtained for the considered model to the exact solution obtained in the classical case. The derived conclusions are further subjected to illustrative graphical and numerical examinations.