What is Illumination?The luminous flux received by the surface per unit area is known as illumination. Illumination is denoted by the letter ‘E’ and is measured in lux or lumen per square meter or meter candela or foot candela.Mathematically, illumination is given by the formula, $$\mathrm{\mathit{E}\:=\:\frac{\mathrm{Luminous\:Flux}}{\mathrm{Area}}}$$Practically, the illumination deals with ... Read More

For a commercial lighting design to be successful, each area of the building must have a sufficient level of light to allow users to perform their tasks. Thus, to determine the desired illumination, proper lighting calculations are to be made.There are a number of methods employed for lighting calculations, the ... Read More

The filament is the most important part of an incandescent lamp. The life of the incandescent lamp depends upon its filament. The ideal material used for the filament of the incandescent lamps is the one which has the following properties −It should have high melting point.Low temperature coefficient.High resistivity.Low vapor ... Read More

Electroslag welding (ESW) is a high productive and single pass welding process, in which the heat required for welding is generated by passing an electric current between the consumable electrode and the workpiece through a molten slag covering the weld surface.The Electroslag welding process is mainly used for welding of ... Read More

Electro Gas Welding (EGW) is continuous arc welding process in which an electric arc is struck between a consumable electrode and the workpiece. The electro gas welding was developed in 1961. It is a vertical position arc welding process. In case of electro gas welding, a shielding gas is sometimes ... Read More

Electric Discharge LampsA lighting device consisting of a transparent container within which a gas is energized by applying an electric voltage and thereby made to glow is known as electric discharge lamp. The electric discharge lamp is also known as vapor lamp or gas-discharge lamp.Actually, the electric discharge lamp is ... Read More

LED BulbLED stands for Light Emitting Diode. The LED bulb has a P-N junction diode which produces light when an electric current passes through it. In LED bulb, when forward bias is applied to the PN junction, the recombination of charge carriers takes place. The result of this recombination of ... Read More

Incandescent BulbIncandescent bulb is a type of filament lamp which produces light by heating a filament made up of metals. The incandescent bulb operates on the principle of incandescence, which is the emission of light by heating metal filament.Incandescent lamps were the first type of electric illumination and invented by ... Read More

In this article, we will compare and contrast the various features of different types of light sources such as incandescent lamps, fluorescent lamps, sodium vapor lamps and mercury vapor lamps.Starting and StoppingIncandescent lamps have instantaneous start and they become momentarily off when the power supply cuts off.Fluorescent lamps have a ... Read More

Arc WeldingA welding process in which an electric arc is used to produce heat to melt and join the metals is known as arc welding. In the arc welding, an AC or DC welding power supply is used to create the electric arc between a consumable or non-consumable electrode and ... Read More