(a)LED: Led is light emitting diode. It is a pn junction diode, which emits light when gets activated. When a suitable energy is applied , electron combines with the electron holes within the device releasing energy in the form of photons.LED lamps have a lifespan and electrical efficiency which are several times longer than incandescent lamps, and significantly more efficient than most fluorescent lamps.
(b)Insulated Gate Bipolar transistor: It is a transistor device and forms the basic component of all electronic devices. It used to amplify or switch electronic signals and electric power. IGBTs is also used to generate the ( mercury) discharge, which lights up the bulb. It can also fit in a small volume.
(c)Properties of tungsten: Tungsten has a very high melting point , it has low vapor pressure and greatest tensile strength out of all the metals. Because of these properties tungsten is used as filament in incandescent bulb.
BPCS Notes brings Prelims and Mains programs for BPCS Prelims and BPCS Mains Exam preparation. Various Programs initiated by BPCS Notes are as follows:-