This paper presents an instrument made up of Excel spreadsheets used to study the relativistic transformation of the electromagnetic field. Knowing the electric and magnetic components of an electromagnetic field in an inertial reference frame, we can determine the components of the same electromagnetic field in another inertial reference frame. Two sets of input data are utilized. The former is made up of the components of the electric and magnetic field in the reference frame considered to be fixed. The latter is made up of the components of the velocity of the reference frame considered to be mobile in relation to the fixed reference frame. The results are expressed both numerically and graphically through charts in the main spreadsheet. The charts comparatively present the components of the electric, respectively magnetic, field in the two reference frames. The instrument can contribute to the fixation and consolidation of students' knowledge regarding the structure of the electromagnetic field. Thus it is verified that the orthogonality property of the electric and magnetic field vectors is one invariantly relativistic. Moreover, it is verified that we cannot transform a purely electric field in a purely magnetic one and the other way around through any Lorentz transformation. Exploring the facilities of spreadsheets, we can elaborate with them new instruments to help us in the teaching and learning of fundamental concepts of Physics. The presented instrument represents a good example of rendering, in an interactive way, certain aspects of the connection between Electromagnetism and the Special Theory of Relativity. With its help, a series of particular cases can be analyzed so that students gain a new learning experience and be motivated in the study of Physics.

Excel Spreadsheets, electromagnetic field, didactic interactive tool, Physics Education.