Tnpsc and Upsc Notes Pdf
Pravin Babu R 
Neolithic Sites in India and Their Culture The Neolithic Age means the New Stone Age and the last part of the Stone Age. It spanned around 7000 BC. There are four main groups of sites found in India. The Neolithic settlement was found in northwest India, South India, and North-Eastern India. The important sites were … Read more
Lower Palaeolithic Culture During the lower Palaeolithic times, Upright man is believed to have lived in the Indian Subcontinent. To add more strength to this theory, we found the first Palaeolithic tools in Pallavaram in Chennai, India, identified by Robert Bruce Foote in 1863, and then many Palaeolithic sites were discovered in India’s subcontinent. Lower Paleolithic … Read more
North east monsoon in India North east monsoon in India is also called as Post Monsoon or Retreating Monsoon. The southwest monsoon starts in North India by the end of the second half of September because of the southward shifting of pressure belts. This wind gets backs from the Indian peninsula and blows towards the … Read more
Direction of South West monsoon in India The Bay of Bengal wind moves to northeast India, Myanmar and this wind is trapped by mountain groups such as Khasi, Garo, and Jaintia. This results in the heaviest rainfall in the world, that is Mawsynram located in Meghalaya. Then it moves to the west, which results in … Read more
Theory of plate tectonics The theory of plate tectonics is a scientific theory that explains the formation of major landforms due to the earth’s underlying movements. What is the theory of plate tectonics? The interest in the distribution of oceans and continents came to life after the introduction of the concept of seafloor spreading. After … Read more
Seafloor spreading definition The formation of new areas of oceanic crust happens by the upcoming magma at mid-ocean ridges and its outward movement on either side. The constant eruption by volcanoes at the crest of oceanic ridges causes cracks or ruptures of the oceanic crust. Then lava is filled into the cracks of oceanic ridges. … Read more
Helium-Neon Laser Helium-Neon Laser or He-Ne Laser is a gas laser. That uses Helium and Neon. It operates at a wavelength of 632.8 nm in the red part of the visible spectrum. And it is the first continuous wave (CW) laser constructed. Helium Neon Laser construction and working A continuous and strong laser beam can … Read more
Ruby laser construction and working The Ruby laser was developed in 1960 by T.Maiman. It is made of a single-crystal of ruby rod. The dimensions are 10cm in length and 4.4 cm in Radius (8.8 cm diameter). Ruby is nothing but a crystal of Aluminium oxide Al2O3. In this system, Al3+ ions are replaced by … Read more
Continental drift theory It is a Hypothesis, theory regarding the formation of the continents. When we look at the shape coastline of the Atlantic Ocean, the symmetry of the coastlines on either side of the ocean creates a curiosity in us. This made many scientists think that the Two American continents, Europe and Africa were … Read more
Forest in Tamil Nadu In Tamilnadu, the forest into divided into three major groups as per the temperature. They are Tropical Forest, Montane Subtropical forest, and Montane Temperate Forest. These are further divided based on moisture and physio-gnomic variations. Tropical Evergreen Forest The tropical evergreen forest is found in the regions which receive heavy rainfall. … Read more