The aim of this study was to determine the impact of three different software simulations for studying Ohm's law and connecting resistors on students' academic performance. A total of 168 eighth-grade pupils were divided into three groups. The first group used the software containing the simulation with an already created electrical circuit, an electronic test and feedback. The second group used the software containing the simulation in which students create an electrical circuit, an electronic test and feedback. The third group used the software containing only a simulation in which students create an electrical circuit, but testing and feedback were provided in a traditional way (instructions and feedback from the teacher). Results showed that the simulation software used by the second group had a significantly better effect on students' achievement than other simulation software. This result indicates that simulations allowing for construction of electrical circuits have a greater influence on students' academic performance than simulations with an already created electrical circuit. Also, simulations with computer feedback have a greater influence on students' academic performance than simulations in which feedback is provided by the teacher.