The book contains: P-N Junction diode: Qualitative Theory of P-N Junction, P-N Junction as a diode, diode equation, volt-amper characteristics temperature dependence of V-I characteristic, ideal versus practical ¿ resistance levels (static and dynamic), transition and diffusion capacitances, diode equivalent circuits, load line analysis, breakdown mechanisms in semiconductor diodes, zener diode characteristics. Special purpose electronic devices: Principal of operation and characteristics of Tunnel Diode with the help of energy band diagrams, Varactar Diode, SCR and photo diode RECTIFIERS, FILTERS: P-N Junction as a rectifier, Half wave rectifier, full wave rectifier, Bridge rectifier, Harmonic components in a rectifier circuit, Inductor filter, Capacitor filter, L-section filter, section filter and comparison of various filter circuits, Voltage regulation using zener diode. BIPOLAR JUNCTION TRANSISTOR: the Junction transistor, Transistor current components, Transistor as an amplifier, Transistor construction, Input and Output characteristics of transistor in Common Base, Common Emitter, and Common collector configurations.