CONCEPT MAP

A branching diagram roots the whole unit at two parallel top-level strands born from the band-theory classification -- Metals, Semiconductors and Insulators under 'Energy Bands' -- with the Semiconductors branch splitting into Intrinsic and Extrinsic (further split into p-type and n-type). A second major strand hangs 'Diodes' off Semiconductors, splitting into the p-n junction diode (with its own Characteristics and Applications leaves) and Special purpose diodes (Zener Diode, Rectifier, LED, Photo diode, Solar cell). A third strand hangs 'Transistors' off Semiconductors, splitting into NPN and PNP types, with a further leaf for Switch, Amplifier and Oscillator applications. A fourth strand covers 'Logic gates' (AND, OR, NOT, Ex-OR, NAND, NOR) alongside 'Boolean algebra' and 'De Morgan's theorems', visually tying the whole chapter's device …