This comprehensive course on “Principles of Electrical Sciences” covers both basic electrical and electronics engineering. The content of the course covers almost all the topics of basic electrical engineering, ranging from circuits to electrical machines and measuring instruments. An introduction to basic electronics has also been discussed so as to prepare the students for an in-depth study later. The course is about basic electronic circuits, both analog and digital. In the analog part; diode circuits, BJT amplifiers, signal generators and analog electronic instruments have been covered. The digital part covers digital techniques and details about microprocessors. In this course, easy explanation of topics, plenty of examples and illustrations are also discussed.