Chapter - 1
Water is one of the most important abundant natural resource on earth. Although water is on two-third part of the earth and remaining one-third is land, yet the availability to access portable or freshwater for people is narrowing and consolidating day by day. Polluted or brackish water is responsible for most of the diseases in human. Now days, most of the country in world are facing a huge problem of water infrequency. This infrequency is because of pollution created by manmade hustle. Adequate quantity and reliability of drinking water supply is the fundamental need of all people in this world. Fresh water which was obtained from rivers, lakes and ponds is becoming scarce because of industrialization and population…show more content… The sun lies at the centre of the solar system, where it is by far the largest object. It holds 99.8 percent mass of the solar system. It is a sphere of hot gases mostly hydrogen and helium with a diameter of 1.39x10^9 m on an average, at a distance of 1.5x10^11 m from earth. The Sun is a G2V star, with G2 indicating its surface temperature of approximately 5,778 K (5,505 °C, 9,941 °F). This temperature is due to continuous fusion reaction inside it's core. The energy produced from the sun is radiated into space this energy is calculated by Stefan-Boltzmann law which is
Where, ε = Emissivity of the surface, σ = Stefan-Boltzmann constant.
Earth, also called the world is the third planet from the Sun, the densest planet in the Solar System, the largest of the Solar System's four terrestrial planets, and the only astronomical object known to accommodate life earth's axis of rotation is tilted the diameter of earth is about of about 12.75 x 10^6 metres. Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane.
Solar Spectrum and Solar Radiation:
Solar radiation is radiant energy emitted by the sun, particularly electromagnetic energy. About half of the radiation is in the visible short-wave part of the electromagnetic spectrum. The other half is mostly in the near-infrared part, with some in the ultraviolet part of the spectrum.