Notes for UPSC-Biosphere, Lithosphere, Hydrosphere, Atmosphere, Motion of the Earth and Weather and Climate

Biosphere

1. The part of the Earth where life exists is called the Biosphere ('bios' means 'life').
2. The Earth is the only planet of the solar system that supports life. Life is possible because of its unique lithosphere, hydrosphere and atmosphere.

Lithosphere

1. The uppermost layer of the Earth's crust which is capable of supporting life is called Lithosphere.
2. The Lithosphere (or land) covers two-sevenths or 29.22% (14,90,41,182 sq. km.) of the total surface area of the earth.

Hydrosphere

1. Hydrosphere (or sea) covers five-sevenths or more accurately 70.78% (36,10,59,226 sq. km.) of the total surface area of the earth.
2. Water is freely available in the gaseous, liquid and solid state.
3. It is necessary for carrying out chemical reactions within the bodies of the living organisms.
4. Water also dissolves and transports nutrients from the soil to the plants.
5. It is used by plants for making food.

Atmosphere

1. The envelope of air that completely surrounds the earth is known as atmosphere.
2. The atmosphere extends to about 1000 km from the surface of the earth. But 99% of the total mass of the atmosphere is found within 32 km.
3. This is because the atmosphere is held by the gravitational pull of the earth.

Motion of the Earth

1. The Earth spins (rotates), west to east on its axis once in 24 hours approximately.
2. The Earth's axis is not vertical. It makes an angle of 23° 30' with the vertical or 66° 30' with the plane of the. Earth's orbit.
3. The Earth's axis always remains pointed in the same direction (towards the Pole Star) as the Earth moves around the Sun. The tilt of the Earth's axis is known as the inclination of the Earth's axis.

Weather and Climate

1. Weather is the description of the atmospheric conditions of a particular place at a particular time for a short period of time.
2. Climate is the composite or integrated picture of the weather conditions over a long period of time.
3. Climatic data is based on calculated averages of data recorded over a period of 35 years. The classical period is 30 years, as defined by WMO.

Notes for UPSC-UPSC IAS General Knowledge

Sr. N.	UPSC IAS General Knowledge
1	Who among the following invented Zero? A. Aryabhatta B. Varahamihira C. Bhaskara I D. An unknown Indian Answer Answer: An unknown Indian [ the most fundamental contribution of ancient India to the progress of civilisation is the decimal system of numeration including the invention of the number zero. This system uses 9 digits and a symbol for zero to denote all integral numbers, by assigning a place value to the digits. This system was used in Vedas and Valmiki Ramayana. Mohanjodaro and Harappa civilisations (3000 B.C.) also used this system..So,we can say Zero is invented by unknown Indian.]
2	Which of the following musical instruments is / are composite or Indo-Islamic in origin ? 1. Sitar 2. Shehnai 3. Tabla 4. Sarangi Choose the correct option from the codes given below: A. 1 & 2 Only B. 1, 3 & 4 Only C. 1, 2 & 3 Only D. 1, 2, 3 & 4 Answer Answer: 1, 3 & 4 Only [Shehnai is not composite or Indo-Islamic in origin.]
3	Which among the following is known as the earliest example of Panchayatana style of temple? A. Dashavatara temple at Deogarh B. Temple at Pathari C. Shatrughneshwara temple at Bhubaneshwar D. Lakshmana temple at Sirpur Answer Answer:Dashavatara temple.Deogarh [The Dashavatara Temple or Vishnu Temple also called Gupta temple at Deogarh. It was built in the Gupta Period (320 to c. 600 AD ). Archaeologists have inferred that it is the earliest known Panchayatana temple in North India. A hindu temple is a Panchayatana one when the main shrine is surrounded by four subsidiary shrines.]
4	Which among the following is the hallmark feature of the Dravida style of temple architecture? A. Shikhara B. Gopuram C. Vimana D. Mandapa Answer Answer : Vimana [Vimana is a term for the tower above the Garbhagriha or Sanctum sanctorum in a Hindu temple in Dravidian style.]
5	Which among the following is / are works of Kalidasa? 1. Ritusamhara 2. Meghaduta 3. Dasakumarcharita 4. Kumarashambhava Choose the correct option from the codes given below: A. Only 1 & 2 B. Only 2, 3 &4 C. Only 1, 2 & 4 D. 1, 2, 3 & 4 Answer Answer : Only 1, 2 & 4 [Dashakumaracharita (The narrative of ten young men) is a prose romance in Sanskrit, attributed to Dandin in the 7th century CE. Dandin is a 6th-7th century Sanskrit author of prose romances and expounder on poetics.]
6	Which among the following is the most famous Bronze Image of Chola Period? A. Murugan B. Nataraja C. Venkateshwar D. Vishnu Answer Answer : Nataraja [Chola art:The most famous of all the bronze icons is that of Nataraja, the Divine Dancer. The symbolism presents Siva as lord of the cosmic dance of creation and destruction.
7	Which among conclusions has been derived from the debasement of the coins and gradual disappearance of gold coins during the post-Gupta period? A. Commodities became cheap B. Gold Mining was stalled C. Money economy was gradually replaced by Barter Economy D. There was a decline in trade Answer Answer : There was a decline in trade [Debasement of the coins and gradual disappearance of gold coins during the post-Gupta period indicates the Decline of Trade.]
8	Which among the following ancient authors has complained of the drain of gold to India (due to trade hegemony of ancient India)? A. Ptolemy B. Nero C. Strabo D. Pliny Answer Answer : Pliny [ The lamentation of the Roman writer Pliny in the 1st century A.D refers to heavy drain of Gold from Roman into India in payment of her imports from India. He writes that the drain of Gold is in return for unproductive luxuries. The Roman gold and silver were steadily drained into South India in exchange not only for spices, but also muslin, silk and other costly luxuries.]
9	In the revenue department of Mauryas, who among the following was in-charge of the collection of all revenues in the empire? A. Sannidhatri B. Pradeshta C. Yukta D. Samahatra Answer Answer : Samahatra [ Mauryan administration: Samaharta – chancellor of the exchequer; responsible for the collection of revenue. The Revenue Department had Samharta who was incharge of the collection of all revenues in the empire]
10	The Pagodas at Mahabalipuram had been constructed by ___? A. Cholas B. Chalukyas of Kalyani C. Pallavas D. Pandyas Answer Answer : Pallavas [Pallava dynasty: the reign of Narasimhavarman I : constructed five rath temples at the port town of Mamllapuram (Mahabalipuram) These are now known as seven raths or Pagodas.]

Notes for UPSC-The Nuclear Fission

Nuclear Fission

Nuclear Fission

• Nuclear fission is a reaction in which the nucleus of an atom splits into smaller parts
• Nuclear fission can either release energy or absorb energy: for nuclei lighter than iron fission absorbs energy, while for nuclei heavier than iron it releases energy
• Energy released can be in the form of electromagnetic radiation or kinetic energy
• The amount of free energy contained in nuclear fuel is about a million times that contained in a similar mass of chemical fuel (like petrol)
• The atom bomb or fission bomb is based on nuclear fission
• Example: fission of Uranium-235 to give Barium, Krypton and neutrons

Nuclear Fusion

• Nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus
• Nuclear fusion can result in either the release or absorption of energy: for nuclei lighter than iron fusion releases energy, while for nuclei heavier than iron it absorbs energy
• Nuclear fusion is the source of energy of stars.
• Nuclear fusion is responsible for the production of all but the lightest elements in the universe. This process is called nucleosynthesis
• Controlled nuclear fusion can result in a thermonuclear explosion – the concept behind the hydrogen bomb
  
• The energy density of nuclear fusion is much greater than that of nuclear fission
  
• Only direct conversion of mass into energy (collision of matter and anti matter) is more energetic than nuclear fusion
• Example: fusion of hydrogen nuclei to form helium