Knowledge growth models, based on primary principles, play a fundamental role in the cognitive sciences. The authors submit an extension of their model (ENKI) from 2005, with the results of the practical testing, which was performed using the method developed for the purpose of model ENKI of solving tasks with immediate feedback. This was applied to the curriculum of parallel configuration of resistors in electrical circuits. There were 73 pupils from six elementary schools in attendance for testing. Analysis based on ENKI indicates that three autonomous units (scopes) were evaluated simultaneously during the assessment. Results showed that 25% of pupils knew the curriculum, 9% of pupils showed no improvement, while 66% of pupils showed an increased success in accordance with the ENKI model (significance level alpha= 0.05). Solving 7.2 typical tasks on average, by a method of immediate feedback resulted in 90% of the pupils mastering the curriculum.