Electrical

LED light Working : (a) Electro luminescent lamps LED : Electroluminescence is the emission of light due to the interaction of an electric-field with a suitable solid. These solids may be panels, Light Emitting Diodes (LEDs), light emitting films. The panels employ microcrystalline powder phosphors based on the compounds like zine sulphide. whereas in case … Read more

Metal Halide Lamp : Metal Halide Lamps Working and Construction This lamp is known as mercury halide or metal halide lamp. It has a short arc tube. Inside it there are series of lamps combined within a single arc-tube with output characteristics of different mixtures of elements. When such metals (like thallium, indium, sodium, dysprosium) are introduced into … Read more

Compact Fluorescent Lamp (Tube) (CFL) : Q. Explain with diagram construction and working of CFL lamp. These are lamps of choice for those looking for an energy efficient alternative to incandescent lamps; they are paired for consuming and little as 1/5th of the power and lasting upto 13 times longer than incandescent lamps. Increasing variety … Read more

Halogen Lamps Halogen lamps are developed filament lamps and are free from drawbacks of filament lamps. Halogen lamp Principle : “Amount of radiations in visible spectrum increases as temperature of incandescent material increases upto 6000°C absolute”. Therefore, any material will be suitable and will have high radiating efficiency which has high melting point. Carbon and tungsten are better … Read more

Neon Sign Tubes Construction : In the form of tube even upto 9 metre length and can be bend in manufacturing process to any shape/shapes. It is a glass tubing consisting of two electrodes normally cylindrical in shape, of iron, steel or copper. It contains neon. Different colours are obtained by varying composition of glass and … Read more

Neon Lamp Principle : “Electrons are emitted from cathode by subjecting the surface of the cathode to very high electric stress so that electrons are forcibly ejected from orbits of atoms against nuclear centrifugal force” Construction and Working : It has two closely spaced electrodes sealed within a soft glass envelope containing neon, at pressure of 8 torr … Read more

Sodium Vapour Lamp : Principle : “Electrons are emitted from cathode by subjecting the surface of the cathode to very high electric stress so that electrons are forcibly ejected from orbits of atom against nuclear centrifugal force”. Construction and Working : It consists of inner tube of U shape fitted with neon gas and globules of sodium. For … Read more

Mercury Vapour Lamp : Q. Explain with neat sketch construction and working of high pressure mercury vapour lamp. Principle : “When mercury discharge under low pressure gives mainly ultraviolet radiations. If pressure is increased to one or two atmospheres, its proportion of radiations in visible spectrum is increased and we get light having bluish tinge”. Construction … Read more