Cellphone is not a play device. It is the strongest of all electronic devices using radio waves. Unlike other wireless devices, Cell phone uses frequency in the Gigahertz range close to the Microwave band. Why it uses this frequency? Cellphone requires strongest signals free from interferences to make continuous link with the far located tower (normally 2 km radius) and the satellite. Just observe the range indicator. It is always moving which indicates the effort to make the link. If it is not getting the link, automatically it will jump to another tower. During this effort, very high bursts of radiating energy will spread around us. This kind of high energy radiation is not seen in any domestic appliances. The problem is severe since the Cellphone is always close to the body.
Most of the sound generated by the human voice organ can be understood by the fellow humans. Actually a spoken word has more meaning than its explanation in the dictionary.We produce sound to express emotion, mental imagery, and language. Human voice is the most natural form of communication involved with environmental and situational reality. The formant frequencies of female are higher than that of the male. Voice tract of the female is shorter than that of the male which causes sharp and clear voice in Females.The fundamental frequency of male voice lies in the range of 85 to 180 Hz while that of the female in the range of 150 to 300 Hz.
Continue reading “Why Female Voice is sharper than that of Male? Fact File 4”
Colour is the visual perception of different wavelengths of light such as red, green etc. Colour derives from the spectrum of visible light which interact with the colour sensitive cells of the retina to give the colour vision. Colour may be defined or quantified based on the degree by which the various colour sensitive cells are stimulated. The science of colour is the Chromatics that includes the perception of colour, origin of colour in the materials and involvement of brain. Colourology is the science of colours and their impact on human beings.
E-Filing is the method of filing official forms though online. With the advancement of the IT, more and more official websites are changing to user friendly for submitting the official as well as personal details through e filing. The method is simple, reliable and saves time and paper work. Income tax returns filing is one typical example. Tax payment is mandatory for all citizens having a fixed income from various sources. In India, the Income Tax department has e-filing portal to file tax returns. Here explains the method of e filing.
Electroluminescence is the Optical and Electrical phenomenon in which a material emits light when current passes through it. This phenomenon is entirely different from the emission of light from bulbs and other light emitting devices. It is resulting from the radiative recombination of electrons and holes in a semi conductor material. The excited electrons then generate Photons which appear as light. LEDs and Phosphor displays are typical examples of electroluminescent lighting.
Continue reading “Fact File 2 – How does Electroluminescent Panel Works?”
Solar cell is a semiconductor device used for harvesting Solar energy to charge battery. It generates current through the excitation of its semiconductor material by the Photon energy of the sunlight.