(i) Many people move to urban areas primarily because cities promise more jobs better schools for poor's children and diverse income opportunities then subsistence forming in rural areas.
(ii) Urbanization drives economic growth and causes people to seek working and investment opportunities in urban areas.
(iii) Local governments are unable to manage urbanisation and migrant workers without an affordable place to live in, dwell in slums.
(iv) The VN.Habitat reports that 43% of urban population in developing countries and 78% of those in the least developed countries are slum dwellers.
(v) Lack of affordable low cost housing and poor planning encourages the supply side of slums.
(vi) Some of the slums in to-days world are a product of urbanisation brought by colonialism.
(vii) Urban poverty, encourages the formation and demand for slums.
(viii) Major natural disasters in poor nations often lead to migration of disaster affected form his to unaffiliated areas, the creation of temporary tent city and slums.

(i) The first Persian attack on Greece failed.
(ii) This was due to the fact that Persian army suffered from disease and lack of food, during its march.
(iii) During the second attack, they avoided the land route and came by sea. 3.

(i) He reversed the policy of discriminatory measures against the Hindus.
(ii) He employed Hindu administrators like Todar Mal in key positions of authority.
(iii) These initiatives earned the emperor the loyalty and trust of the majority community.
(iv) The entire region was brought under a uniform administrative structure.
(v) The political stability increased the economy and trade

(i) The Mughal rule started in 1526 A.D.
(ii) Vijayanagar state, founded in 1336, rose to a great power under Krishnadeva Raya.
(iii) Portuguese established their empire in the East with headquarters at Goa.
(iv) In Tamilnadu, in Madurai, Nayak rule began dividing the Pandya kingdom into seventy two palayams.
(v) The arrival of Jesuit Missions and the work of St. Francis Xavier, as a member of Society of Jesus, led to conversion of fishing community to Christianity (Catholicism) in Thoothukudi region.

One of the most important outcomes of the conquest of Americas by the European colonial powers was the movement of plants, animals, technology, culture and strange diseases between the Americas and Europe or between the New World and the Old World. This is known as Columbian Exchange

(i) Sericulture the silk production by breeding the mulberry silkworm was introduced in the fourteenth and fifteenth centuries.
(ii) By the seventeenth century, Bengal had become one of the largest silk-producing regions in the world.
(iii) In addition, other varieties of silk (like tassar) were also produced.

Excommunication and Interdict were the two instruments used against those who defied the church.

(i) Han Empire once again threw open the silk road for trade.
(ii) A large export trade, mainly in silk, reached as far as the Roman Empire.
(iii) In the north artisans and herders of rival "barbarian" dynasties brought in new techniques like the methods of harnessing horses, use of saddle and stirrup.
(iv) Techniques of building bridges and mountain roads and seafaring.
(v) At the beginning of the Christian Era, the Han Empire rivalled that of Roman in size and Wealth.

The Ring of Fire is a ring of volcanoes around the Pacific Ocean. These volcanoes result from subduction of oceanic plates beneath lighter continental plates, A subduction zone is a place where one plate of oceanic lithosphere is shoved under another plate. As it is shoved into the hotter mantle the plate heats up. The addition of volatiles such as water to the hot overlying mantle causes partial melting and the production of magma. This magma rises up through the over-lying plate to erupt at the surface. Hence, the Pacific Ring of Fire is most seismically and volcanically active.

GPS works by sending radio signals from satellites to ground stations. The distance between the satellites and station is recorded. Over time, these distances change slightly. Scientists can measure the rate of Tectonic Plate movements by recording the time it takes for ground stations to move a given distance.

(i) Coastal zone is exposed to natural forces including cyclones and Tsunamis.
(ii) Cuddalore and Nagapattinam are situated on the Sea-Shore.
(iii) Cuddalore and Nagapattinam are vulnerable to storms.
(iv) During Summer Bay of Bengal subject to intense heat cause to raise the humid and unstable air masses that produce cyclone.

The three principles of Jainism are known as Tri-ratnas. They are Right faith, Right knowledge, Right action.

(i) Coins as a medium of exchange were introduced for the first time in the Sangam Age.
(ii) The coins of the Cheras, the Cholas and the Pandyas, punch-marked coins, and Roman coins form another important source of evidence from the Sangam Age.
(iii) Sometimes coins were protected as a precious wealth.

Biological weathering occurs due to the penetration and expansion of plant roofs, earth worms, burrowing animals (rabbits, rats) and same human activities.

De-merits of federal form of government are,
(a) Federal government in weaker when compared to the unitary government.
(b) Federal government is more expensive.
(c) Provincial tendencies are very common
(d) Lack of uniformity in Administration
(e) Threat to national unity
(f) Distribution powers between centre and states lead to conflict
(g) Double Citizenship
(h) Rigid constitution cannot be amended easily for the changing needs.
(I) The state governments sometimes place hindrances in the foreign policy.

(i) Wildfires occur when vegetated areas are set alight and are particularly common during hot and dry periods.
(ii) They can occur in forests, grasslands, bush and deserts, and with sufficient wind can rapidly spread.
(iii) Fires can lead to the destruction of buildings, wooden bridges and poles, power, transmission and telecommunication lines, warehouses of containing oil products and other fuel. It causes. injury to people and animals.
(iv) The most common causes of fires are lightning strikes, sparks during arid conditions, the eruption of volcanoes, and man-made fires arising from deliberate arson or accidents.
(v) A side-effect of wildfires that also threatens inhabited areas is smoke.
(vi) Fires create large quantities of smoke, which can be spread far by wind and poses a respiratory hazard.

(i) A tsunami can kill or injure people and damage or destroy buildings and infrastructure as waves come in and go out.
(ii) A tsunami is a series of enormous ocean waves caused by earthquakes, underwater landslides, volcanic eruptions, or asteroids.
(iii) Tsunamis can travel 700-800 per hour with waves 10-30 meter high.
(iv) It causes flooding and disrupts transportation, power, communications, and the water supply.

Agriculture, despite a sharp decline in gross domestic product, continues to be the largest employer in Tamil. Nadu. This is because the non-agriculture sectors are yet to generate enough employment to affect a shift of labour force.

(i) NNP - Net National Product
(ii) PCI - Per Capita Income

Abraham Lincoln defines democracy as a government of the people, by the people and for the people