This course is offered both to undergraduates (6.061) and graduates (6.979), where the graduate version has different problem sets and an additional term project. 6.061 / 6.979 is an introductory course in the field of electric power systems and electrical to mechanical energy conversion. Material encountered in the subject includes: Fundamentals of energy-handling electric circuits and electromechanical apparatus. Modeling of magnetic field devices and description of their behavior using appropriate models. Simplification of problems using transformation techniques. Power electric circuits, magnetic circuits, lumped parameter electromechanics, elements of linear and rotating electric machinery. Modeling of synchronous, induction and dc machinery. The course uses examples from current research.