At temperatures above absolute zero, some electrons are excited out over the band gap into the conduction band. When the electron in pure silicon crosses the gap, it creates a vacancy, known as a hole, in the regular silicon lattice. A hole means actually nothing. But since it can accept an electron to get occupied into it, it is assumed to have a positive charge.
Read MoreCrystal Structure & Behavior of semiconductor
The average value of a waveform, which swings symmetrically above and below zero, will be obviously zero, when measured over a long period of time. Hence, average values of currents and voltages are invariably taken over one complete half-cycle (either positive or negative) rather than over one complete full-cycle (which would result in an average value of zero).
Read MoreWhat is Peak, R.M.S. & Average Value of ac voltage and current
Transistor is a semiconductor device having three layers, three terminals and two junctions. Since we have only two types of semiconductors i.e. the p-type and n-type, there are two types of transistors: they are NPN transistor and PNP transistor.
Read MoreHow NPN transistor works? Tutorials of forward & reverse biasing of an NPN transistor
