In this textbook, 203 Problems and 5 Projects are presented. Most of them concern practical cases to increase the student's motivation to broaden their practical knowledge. Answers are provided for all problems and are hidden behind QR codes. This textbook contains also links to simulations, videos and digital documents necessary to better understand and solve problems. It can be used by undergraduate students of first level of electrical and electronics engineering or by teachers for making the lessons closer to our daily life.