The objective of the present study is to identify the mental models applied by students using Coulomb's law and the electric field concept to interpret electrostatic phenomena at the beginning of a second-year engineering course. Results indicate that most students do not correctly apply the symmetry of Coulomb's law. Although they have a coherent mental model, their version is not consistent with that which is scientifically accepted, and they confuse the concept of the electric field with the force between charges.

Key words: Mental models, alternative conceptions, engineering education.