The book 'Electronic Principles' is a comprehensive textbook for the students of B. E., B. Tech, B.Sc., diploma and various other Engineering Disciplines. The book provides an in-depth coverage and comprehensive discussion on essential concepts of Electronics Engineering. The book begins with detailed explanation of classification of semiconductors, transport phenomena in semiconductor and Junction diodes. It also covers circuit modeling techniques for bipolar junction transistors, used in designing amplifiers. The textbook discusses design construction and operation principle for junction gate field-effect transistor, silicon controlled rectifier and operational amplifier. It also includes chapters on Introduction to logic circuits, De Morgan's theorem and digital circuits. Applications of oscillators, silicon controlled rectifier and operational amplifier have also been covered in great details. Pedagogical features including solved problems, multiple choice questions and unsolved exercises are interspersed throughout the book for better understating of concepts. This text is the ideal resource for first year undergraduate engineering students taking an introductory course in fundamentals of electronics engineering/principles of electronics engineering.