Physical Geography Notes pdf Download For UPSC IAS Exam

CONTENTS
1. Our Universe
2. Interior Infrastructure of Earth ...
3. Mineral & Rocks ...
4. Forces Effecting the Earth Movements
5. Weathering & Erosion. ..
6. Geogmorphological Landforms ....
7. Volcanoes Earthquakes .
8. Erosional and Depositional Landforms.
9. Drainage System & Patterns .
10. Atmosphere
11. Climate Classification
12. Hydrosphere
13. Soil.
14. Natural Vegetation .
15. Population ....
16. Human Settlement..
17. Agriculture. .
18. Fisheries.
19. Minerals
20. Industries
21. Energy Resources .
22. Transport .

OUR UNIVERSE
The big bang theory explains the origin of our universe. According to this theory, 15 billion years ago, cosmic matter was in a compressed state from which expansion started by a primordial
explosion. The super-dense ball broke to form galaxies, which again broke to form stars andf inally stars broke to form planets including earth.
Since the outer space is limitless, conventionalu nits for measuring distances are not suitable.
Hence new units as follows are used:
• Light Year: Distance covered by light in
one year in vacuum at a speed of 3x108
m/s. One light year is equal to 9.46 ×
1012 kilometers.
• Astronomical Unit: The Mean distance
between the Sun and the Earth (1.49 x
108km). One light year is equal to 60,000
AU.
• Cosmic Year: Sun's period of revolution
around the galactic centre (250 million
years). Also called as 'galactic year'
• Parsec: Distance at which the mean ra-
dius of the Earth's orbit subtends an
angle of one second of an arc. It is equal
to 3.26 light years.
Galaxies .These are huge congregation of stars that hold together by force of gravity e.g. the Milky Way, Andromeda galaxy, large and small magellanic cloud, Ursa Minor system, sculptor system, etc. Milky Way or Akashganga is our home galaxy. Our solar system is located in this galaxy.Stars Stars are self luminous bodies that account for 98 percent of the matter in a galaxy. In the universe, some stars appear small but emit more energy than the other stars of the Milky Way. Such stars are called 'Quasars'. When the dense
galactic nucleus is compressing to form a star, this stage in star formation is called a 'protostar' stage. Due to high temperature hydrogen converts to
helium and heat and light is emitted. Thus a star is formed. When the hydrogen of a star is depleted,
its outer regions swell and redden. This stage of a star is called a 'Red Giant'. Our sun will turn into a 'Red Giant' in 5 billion years. 'Novae Stars' are stars whose brightness increases suddenly by 10 to 20 magnitudes due to explosion and then the stars again fade into normal brightness. 'Super Novae' are stars whose brightness suddenly increases by more than 20 magnitudes. After the explosion, the dense core of comparatively smaller
stars is called the 'white dwarf'. The dense core of the comparatively larger stars is called the 'Neutron star'. The neutron star rotates at a high speed emitting radio waves. Such stars are called 'Pulsar'. 'Black hole' stage of the star occurs when the ancient star collapses. Gravity becomes so intense in the hole that nothing escapes, evenl ight.Constellation