Vasantha

Chapter 1 Earth As A Planet Multiple Choice Questions

Question 1. The Earth’s’equatorial diameter is

1. 12,712 km
2. 12,745 km
3. 12,757 km
4. 12,500 km

Answer: 3. 12,757 km

Question 2. The Earth’s polar diameter is

1. 12,400 km
2. 12,714 km
3. 12,700 km
4. 12,720 km

Answer: 2. 12,714 km

Read and Learn Also WBBSE Class 9 Geography And Environment Multiple Choice Questions

Question 3. The Earth revolves around the Sun.” This was first stated by

1. Galileo
2. Copernicus
3. Aryabhatta
4. Varahamihir

Answer: 3 Aryabhatta

Question 4. The highest point on the surface of the Earth is

1. Mount Everest
2. Pamir Plateau
3. Tibetan PJateau
4. North Pole

Answer:1. Mount Everest

Question 5. The deepest known point on the Earth is

1. Mariana Trench
2. Sunda Trench
3. St. Louis Trench
4. South Pole

Answer: 1. Mariana Trench

Question 6. The difference between the Earth’s polar diameter and the equatorial diameter is

1. 40 km
2. 42 km
3. 43 km
4. 45 km

Answer: 3. 43 km

Question 7. The Bedford Canal Experiment was carried out by

1. Wallace
2. Torricelli
3. Foucault
4. Galileo

Answer:1. Wallace

Question 8. The average circumference of the Earth is

1. 40,400 km
2. 40,075 km
3. 40,500 km
4. 40,200 km

Answer:2. 40,075 km

NEET Biology Class 9 Question And Answers	WBBSE Class 9 History Notes	WBBSE Solutions for Class 9 Life Science and Environment
WBBSE Class 9 Geography And Environment Notes	WBBSE Class 9 History Multiple Choice Questions	WBBSE Class 9 Life Science Long Answer Questions
WBBSE Solutions for Class 9 Geography And Environment	WBBSE Class 9 History Long Answer Questions	WBBSE Class 9 Life Science Multiple Choice Questions
WBBSE Class 9 Geography And Environment Multiple Choice Questions	WBBSE Class 9 History Short Answer Questions	WBBSE Solutions For Class 9 Maths
WBBSE Solutions for Class 9 History	WBBSE Class 9 History Very Short Answer Questions	WBBSE Solutions for Class 9 Physical Science and Environment

 

Question 9. In ancient times, people believed that the Earth was a

1. Sphere
2. An oblate spheroid
3. Plane
4. Square

Answer: 3. plane

Question 10. The ancient Mesopotamians believed that the Earth was

1. Floating in space
2. Floating on an ocean
3. A single entity standing on its own
4. Not floating anywhere

Answer: 2. floating on an ocean

Question 11. “The Earth is round.” This statement was first made by

1. Plato
2. Pythagoras
3. Aristotle
4. Strabo

Answer: 2. Pythagoras

Question 12. Pythagoras was a

1. Greek philosopher
2. Roman philosopher
3. British philosopher
4. Portuguese philosopher

Answer: 1. Greek philosopher

Question 13. The first empirical proof that the Earth is round was given by

1. Pythagoras
2. Magellan
3. Columbus
4. Aristotle

Answer: 2. Magellan

Question 14. An example of proof that the Earth is round is

1. The view from the mast of a ship
2. Travelling around the world on a ship
3. Photographs were taken from space
4. The view from the top of Mt. Everest

Answer: 3. Photographs taken from space

Question 15. The person to calculate the Earth’s circumference on the basis of the difference in the angle of incidence of Sun rays was

1. Strabo
2. Aristotle
3. Eratosthenes
4. Plato

Answer: 3. Eratosthenes

Question 16. The Old Bedford River is in

1. England
2. France
3. Germany
4. Italy

Answer: 1. England

Question 17. The Earth can be called an oblate spheroid because

1. The Earth’s surface is elevated by 15 m at the North Pole
2. There is more water in the equatorial region
3. The highest point on Earth is Mt. Everest
4. The Poles are flattened and the equatorial region is bulging out

Answer: 2. there is more water in the equatorial region

Question 18. The Earth’s gravitational force is the greatest

1. At the equatorial region
2. In the ocean beds
3. On mountain peaks
4. At the Poles

Answer: 4. at the Poles

Question 19. The pendulum clock experiment was conducted by

1. Pythagoras
2. Eratosthenes
3. Jean Richer
4. Galileo

Answer: 3. Jean Richer

Question 20. The word ‘geoid’ means

1. An oblate spheroid
2. Perfect sphere
3. Flattened
4. Like the Earth

Answer:4. like the Earth

Question 21. One of the believers in the Earth-centric model of the universe was

1. Copernicus
2. Aristotle
3. Bruno
4. Brahe

Answer: 2. Aristotle

Question 22. The telescope was invented by

1. Kepler
2. Galileo
3. Newton
4. Halley

Answer: 2. Galileo

Question 23. If we move 111.3 kilometres from the Equator towards the Poles, the angle of incidence of the Sun’s rays will increase by

1. 1° 30′
2. 2° 30′
3. 1°
4. 1° 02′

Answer: 3. 1°

Question 24. The latitudinal coordinate of Paris is

1. 26° 32′ N
2. 47° N
3. 49° N
4. 75° 03′ N

Answer: 3. 49° N

Question 25. The Cayenne Islands are in

1. North America
2. South America
3. Asia
4. Austria

Answer: 2. South America

Question 26. The deepest point in the Mariana Trench has a depth of

1. 10,053 m
2. 11,035 m
3. 11,350 m
4. 10,994 m

Answer: 2. 11,035 m

Question 27. The Earth’s centrifugal force is greatest at the

1. Equatorial region
2. Tropics
3. Polar regions
4. Frigid zone

Answer: 2. tropics

Question 28. During a lunar eclipse, the shadow of the Earth on the Moon looks

1. Straight
2. Curved
3. Circular
4. Rectangular

Answer: 3. circular

Question 29. As we go higher up from the surface of the Earth, the line of horizon appears

1. Shorter
2. Longer
3. Stays the same
4. None of the above

Answer: 2. longer

Question 30. Eratosthenes was

1. A Roman philosopher
2. Greek philosopher
3. An Egyptian philosopher
4. An Indian philosopher

Answer: 2. Greek philosopher

Question 31. Real shape of the Earth is

1. Spherical
2. Flat
3. An oblate spheroid
4. Rectangular

Answer: 3. oblate spheroid

Question 32. Columbus was a tourist from

1. France
2. Japan
3. Portugal
4. Spain

Answer:4. Spain

Question 33. Branch of Mathematics in which the shape and size of the Earth are discussed, is known as

1. Geodesy
2. Geology
3. Geography
4. Geophysics

Answer:1. Geodesy

Question 34. Bedford Canal experiment was conducted in

1. 1770
2. 1870
3. 1920
4. 1750

Answer: 2. 1870

Question 35. World’s first astronaut was

1. Yuri Gagarin
2. Rakesh Sharma
3. Neil Armstrong
4. Michael Collins

Answer:1. Yuri Gagarin

Question 36. The world’s first woman astronaut was

1. Koalpana Chaula
2. Sunita Williams
3. Valentina Tereshkova
4. Christinach

Answer: 3. Valentina Tereshkova

Question 37. The angle of elevation of the Pole Star from the Equator is

1. 0°
2. 15°
3. 60°
4. 90°

Answer: 1. 0°

Question 38.”The Earth is a floating disc in water.”This statement was put forth by

1. Thales
2. Anaximander
3. Ptolemy
4. Hecataeus

Answer: 1. Thales

Question 39. Eratosthenes is the father of

1. Geology
2. Geography
3. Geodesy
4. Geophysics

Answer: 3. Geodesy

Question 40. The weight of any material on the Earth’s surface is maximum at the latitude of

1. 0°
2. 23
3. 66
4. 90°

Answer: 4. 90°

Question 41. The ‘Blue Planet’ is another name for

1. Earth
2. Venus
3. Saturn
4. Mars

Answer: 1. Earth

Question 42. The planet nearest to the Earth is

1. Mercury
2. Venus
3. Mars
4. Jupiter

Answer: 2. Venus

Question 43. The planet closest to the Sun is

1. Mercury
2. Pluto
3. Venus
4. Neptune

Answer: 1. Mercury

Question 44.”The Earth revolves around the Sun and on its own axis.” The first person to say this was

1. Copernicus
2. Aryabhatta
3. Galileo
4. Newton

Answer: 1. Copernicus

Question 45. The average distance of the Earth from the Sun is

1. 140 million km
2. 150 million km
3. 160 million km
4. 120 million km

Answer: 150 million km

Question 46. An example of a dwarf planet is

1. Pluto
2. Mercury
3. Mars
4. Neptune

Answer: Pluto

Question 47. The average radius of the Earth is

1. 6,300 km
2. 6,371 km
3. 6,500 km
4. 6,600 km

Answer: 2. 6,371 km

Question 48. In 1797, scientist Henry Cavendish determined the Earth’s

1. Density
2. Weight
3. Circumference
4. Diameter

Answer: 4. Diameter

Question 49. In terms of distance from, the Sun, the Earth is a planet.

1. Second
2. Third
3. Fourth
4. Fifth

Answer: 2. Third

Question 50. The Sun is a

1. Planet
2. Satellite
3. Star
4. Galaxy

Answer: 3. Star

Question 51. The Sun is heavier than the Earth by

1. 0.35 million times
2. 0.33 million times
3. 0.32 million times
4. 0.325 million times

Answer: 0.33 million times

Question 52. The number of Jovian planets in the solar system is

1. 7
2. 8
3. 9
4. 6

Answer: 2. 8

Question 53. The planet which has rings around it is

1. Saturn
2. Earth
3. Mercury
4. Venus

Answer: 1. Saturn

Question 54. The name of one satellite of Saturn is

1. Moon
2. Titan
3. Haumea
4. Phobos

Answer: 2. Titan

Question 55. The total number of components in a GPS is

1. 3
2. 6
3. 4
4. 5

Answer: 1. 3

Question 56. The shape of Mercury and Venus is

1. A oblate spheroid
2. Perfect sphere
3. Geoid
4. Flattened

Answer: 2. Perfect sphere

Question 57. To complete one Sun, Venus takes

1. 365 days
2. 24 hours
3. 243 days
4. 27 days

Answer: 3. 243 days

Question 58. To complete one revolution around the Earth, the Moon takes

1. 36 days
2. 20 days
3. 27 days
4. 27 days

Answer: 3. 27 days

Question 59. The length of the Earth’s orbit is

1. 9.6 million km
2. 11 million km
3. 14.70 million km
4. 15.20 million km

Answer: 1. 9.6 million km

Question 60. To determine the location of any place on Earth using GPS, the number of satellites launched in space by the USA is

1. 23
2. 24
3. 25
4. 31

Answer: 1. 23

Question 61. The largest planet in the solar system is

1. Mercury Venus
2. Venus
3. Jupiter
4. Mars

Answer: 3. Jupiter

Question 62. At present, the number of known planets in the solar system is

1. 3
2. 5
3. 7
4. 8

Answer: 4. 8

Question 61. At present, the number of dwarf planets in the solar system is

1. 5
2. 6
3. 4
4. 3

Answer: 1. 5

Question 62. Biosphere is extended above the surface upto

1. 15 km
2. 10 km
3. 20 km
4. 23 km

Answer: 1. 15 km

• Chapter 1 Earth As A Planet Notes
• Chapter 2 Movements Of The Earth Notes
• Chapter 3 Determination Of Location Of A Place Of The Earth’s Surface Notes
• Chapter 4 Geomorphic Process And Landforms Of The Earth Notes
• Chapter 5 Weathering Notes
• Chapter 6 Hazards And Disasters Notes
• Chapter 7 Resources Of India Notes
• Chapter 8 West Bengal Notes

 

Chapter 8 West Bengal Introduction

West Bengal is the only state of India that extends from the Bay of Bengal to the Himalayas.

At present, there are 28 states and 8 union territories in India.

West Bengal ranks fourth in total population and second in population density among the 28 states of India.

West Bengal shares common boundaries with three independent countries namely, Bangladesh, Bhutan, and Nepal, and five

Indian states namely, Assam, Sikkim, Bihar, Jharkhand, and Odisha. Though the state of Tripura does not share a common boundary with West Bengal, it is regarded as a neighboring state of West Bengal.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

Presently, there are 23 districts in West Bengal which are grouped into 5 administrative divisions—

Jalpaiguri division,

Malda division,

Bardhaman division,

Medinipur division,

Presidency division.

The most newly formed districts of West Bengal are Purba Bardhaman and Paschim Bardhaman which were formed on 7 April 2017 after the bifurcation of the former Bardhaman district.

West Bengal is mainly divided into three physiographic divisions—

Northern hilly region,

Western plateau region and

Plain region.

The northern hilly region of West Bengal is the extended part of the eastern Himalayas. This mountainous region covers the major part of Darjeeling district except for the Siliguri subdivision, Kalimpong district, and the northern part of Alipurduar district.

Singalila range extends along the boundary of Darjeeling and Nepal. Sandakphu, one of the peaks of the Singalila range (3665 m) is the highest peak in West Bengal.

The plain land at the foothills of the northern hilly region is known as Terai. The slope of the land is from north to south. The land at the east of Terai is known as Dooars or Duars.

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WBBSE Solutions for Class 9 Geography And Environment	WBBSE Class 9 History Long Answer Questions	WBBSE Class 9 Life Science Multiple Choice Questions
WBBSE Class 9 Geography And Environment Multiple Choice Questions	WBBSE Class 9 History Short Answer Questions	WBBSE Solutions For Class 9 Maths
WBBSE Solutions for Class 9 History	WBBSE Class 9 History Very Short Answer Questions	WBBSE Solutions for Class 9 Physical Science and Environment

 

WBBSE Class 9 Geography Chapter 8 West Bengal Notes

Geologically western plateau region is a part of the Chotanagpur Plateau.

Gorgaburu of Ayodhya hill is the highest peak (677 m) of the western plateau region.

The old alluvium region of North Bengal is called Barind or Barendrabhumi. Red soil can be seen in this region.

The scattered marshy land of the northern plain is locally known as Tal.

The flat land between the western plateau region and the Bhagirathi-Hooghly River is known as the Rarh region.

Sagar Island is the largest island and Purbasha or New Moore Island (currently submerged) is the newly formed island of the Sundarban region.

The main river of West Bengal is Ganga and its tributary Bhagirathi-Hooghly.

Teesta is the main river of the northern hilly region which originated from the Jemu glacier of the Himalayas.

Teesta is also known as the ‘River of Threat’ as it causes floods during monsoons in the northern hilly region.

Many rivers flow along the slope of the western plateau. Damodar is the main river among them.

Damodar originates from the Khamarpat. Hill of Jharkhand. It is also known as the ‘Sorrow of Bengal’ as it causes massive floods during the rainy season.

The combined flow of the Dwarakeswar and Shilabati rivers is known as the Rupnarayan river.

In the coastal region of West Bengal, the rivers become wider at their mouths and form funnel-shaped creeks.

Most of the rivers in a northern hilly region are snow-fed and thus, carry water throughout the year.

Most of the rivers of the western plateau region are rain-fed.

Rivers of the Sundarban region are tide-fed.

The influence of monsoon winds is maximum on the climate of West Bengal.

The four seasons summer, monsoon, autumn, and winter occur sequentially in West Bengal.

The southwest monsoon wind blows from June to September and from the end of September to the beginning of October, retreating monsoon wind or northeast monsoon wind blows over West Bengal.

In the summer season, a hot and dry wind known as ‘loo’ blows at noon over the. western plateau region, of West Bengal.

The hottest and coldest places in West Bengal are Asansol and Sandakphu respectively.

Buxaduar of the Alipurduar district is the wettest or the most humid (average annual rainfall 535 cm) place in West Bengal, whereas Mayureswar of the Birbhum district is the driest place.

During summers in West Bengal (April- May), sometimes in the evening thunderstorms and heavy rainfall or hailstorms occur, which are called Nor’wester [locally known as ‘Kalbaisakhi’]. On the other hand, in autumn (October-November) a local cyclone called ‘Aswiner Jhar’ causes rainfall in the coastal regions of West Bengal.

Most of the region in West Bengal is covered by alluvial soil. It is fertile soil with a high water-holding capacity. Alluvial soil is found on both banks of the Bhagirathi-Hooghly River.

Natural Resources And Economy Of West Bengal Notes WBBSE Class 9

Sandy saline soil is found in the coastal regions of Purba Medinipur and South 24 Parganas.

Red, hard lateritic soil is found in the districts of Purulia, Birbhum, Bankura, and Paschim Medinipur. All these districts fall under the plateau region of West Bengal. Laterite soil is rich in iron and aluminum oxide.

Duricrust forms the top hard layer of laterite soil.

Brown podsol soil is found in the northern hilly region of West Bengal. This soil is favorable for the cultivation of tea, cinchona’, oranges, pineapple, etc. Coniferous trees also grow in this type of soil.

Terai soil, which is found at the foothills of the northern hilly region in West Bengal, is full of pebbles and has high nitrogen content.

A characteristic type of landform has developed by soil erosion caused due to rainfall and streamflow near, Shantiniketan in the Birbhum district. This type of topography is called khoai or badland topography.

Only 13% of the total land in West Bengal is under forest cover, out of which 60% of the forest is restricted to the northern hilly region.

Most of the area in West Bengal is covered by deciduous forests. However, the terai-duars region and the high-altitude areas of the northern hilly region are covered by dense evergreen forest and coniferous forest respectively.

The deciduous forest cover of the western plateau region of West Bengal has considerably reduced due to deforestation.

Mangrove or tidal forest is found on the southern coast of North and South 24 Parganas. This mangrove forest is known as Sundarbans for the predominance of Sundari trees.

Sundarbans. mangrove forest was enlisted as a UNESCO World Heritage Site in 1997.

Two-thirds of the whole population of West Bengal is directly or indirectly dependent on agricultural work.

The main agricultural food crop of West Bengal is rice and different types of cash crops grown here are tea, jute, etc.

The variety of paddy that is mainly cultivated in West Bengal is Aman.

Purba Bardhaman district is called the ‘Rice Bowl of West Bengal’.

Rice Research Institute of West Bengal is located at Chinsurah in the Hooghly district.

Jute is known as golden fiber and tea is known as a golden drink.

An institute on jute research is located at Barrackpore in North 24 Parganas.

A tea auction center is located in Siliguri.

Tea Board India is located in Kolkata.

The main source of power for electricity generation in West Bengal is thermal power (heat produced by the burning of coal).

The largest thermal power station in West Bengal is Mejia (estimated total capacity is 2340 MW). Another important power station is Farakka (estimated total capacity is 2100 MW).

Durgapur and Kulti-Burnpur are the main centers of the iron and steel industry in West Bengal. Durgapur is called ‘Ruhr of India’.

The first jute mill in India was set up in 1854 at Rishra. Most of the jute mills in India are found in the Hooghly industrial belt,

The first cotton textile factory in West Bengal as well as in India was established in 1818 at Ghusuri in the Hooghly district.

The cotton textile industry is also called the footloose industry.

Class 9 WBBSE Geography West Bengal Key Concepts And Study Guide

Edward Food Research and Analysis Centre Limited has been established at Barasat in North 24 Parganas to assess the quality of products in the food processing industry.

Software Technology Park has been established in Salt Lake to promote software technology. The Intelligent Complex has also been formed for the same purpose and it covers an area of over 3 lakh square feet.

The state government of West Bengal has launched a campaign named ‘Beautiful Bengal’ to promote tourism in West Bengal in India and also across the world.

The second largest city in West Bengal is Asansol. It is the district headquarters of Paschim Bardhaman and is also called ‘the City of Black Diamond’.

Recently, the construction of the third largest port of West Bengal has been initiated near Sagar island in South 24 Parganas.

Some noteworthy historical places of West.’Bengal is Hazarduari, Plassey, Gour, etc.

Chapter 7 Resource Of India Salient Points Introduction

According to Zimmerman (1957), a famous resource specialist, “Resource does not mean any object or matter, it is its function and process which makes that object or matter beneficial to man by fulfilling his demand.” In other words, the utility or function of any object or matter that is capable of meeting any demand is a resource. Thus ‘Resource is a medium through which a demand is fulfilled, be it an individual or a social demand.

Resources that are available in nature in limited quantities diminish in a continual process of utilization and cannot be replaced after being utilized are called non-renewable or fund or exhaustible resources.

Resources that are easily available in nature and can be used without being depleted, are called renewable or inexhaustible resources. For example- sunlight, wind, sea waves, etc.

The resources that are rare and are available only in one place on the Earth are called uniquities or unique resources.
There are three resource-creating factors—nature, ma,n, and culture.

Materials that are available in nature and are of no use are called neutral stuff.

The phenomena which cause harm to man by hampering the growth of resources are called resistance barriers. Examples—are illiteracy; bigotry; and natural hazards like floods, storms, etc.

The process by which waste materials are converted into new resources is called recycling. For example, broken or damaged iron, and aluminum objects are transformed into new materials by melting in factories.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

Iron ore is a non-renewable or exhaustible resource.

Superior quality iron ore is magnetite (72% iron) and the inferior quality iron ore is siderite (48% iron).

The main basis of all industries are iron and steel industry.

Most of the deposited iron in India is of hematite type.

WBBSE Class 9 Geography Chapter 7 Resources of India Notes

According to recent statistical data from the Indian Bureau of Mines, Odisha is the largest iron ore-producing state in India.

Coal is also known as black diamond as it has multiple uses and importance.

Anthracite is the best quality coal that contains 85%-95% of carbon.

Raniganj in West Bengal- is the oldest coalfield in India and Neyveli in Tamil Nadu is the largest lignite coalfield in India.

Coal and petroleum are found in the sedimentary rock strata.

Although coal is a fossil fuel, it is a sedimentary rock.

At present (2019) India is the second largest coal-producing country in the world after China.

ONGC is the largest oil-producing organization in India.

Crude oil is a naturally occurring unrefined petroleum product composed of hydrocarbon deposits and other organic materials.

Petroleum is also known as liquid gold for its importance.

Except the hydroelectric power, all types of conventional energy pollute the environment.

Hydroelectricity is also known as white coal.

The largest thermal power plant in India is located at Mundra in Gujarat.

The world’s largest thermal power station is located at Taichung in Taiwan state of China.

Three Gorges Dam on the Yangtze River, China is the world’s largest hydroelectric power plant.

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WBBSE Class 9 Geography And Environment Multiple Choice Questions	WBBSE Class 9 History Short Answer Questions	WBBSE Solutions For Class 9 Maths
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WBBSE Geography Resources of India Notes with Important Questions Class 9

The Koyna Hydroelectric Project on the Koyna River, Maharastra is the largest completed hydroelectric power plant in India.

The world’s first nuclear power station is located at Obninsk in Russia.

India’s first or oldest nuclear power station is located at Tarapur in Maharastra.

Non-conventional energies are eco-friendly. Since non-conventional energy does not cause pollution, it is also called Green Energy.

Solar energy is produced with the help of Solar Photovoltaic cells.

Gujarat holds the first position in India for maximum solar energy generation.

Tamil Nadu ranks first in India for maximum wind energy generation.

Chapter 6 Hazards And Disasters Salient Points Introduction

The extreme events that disrupt our normal activities and our daily lives and originate due to natural causes human activities or combined activities of both, are called hazards.

The temporary or permanent events caused by natural or human activities endangering human life causing great damage to life and property, which degrade the quality of the environment and last for a long time, are called disasters.

French word ‘des’ means ‘bad’ and ‘aster’ means ‘star’ and the aggregation of these two words is a disaster (bad star).

Many lives and a huge amount of property were damaged by flash floods on 16 July 2013 in Uttarakhand. It was a disaster.

A huge amount of property was damaged and millions of people were killed due to the Tsunami on 26 December 2004 in the surrounding countries of the Bay of Bengal in south-east Asia.

In 2001, millions of people died due to the earthquake in Bhuj City in Gujarat.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

In 1902, Saint Pierre city was destroyed due to the volcanic eruption of Mt. Pelee volcano in the West Indies.

The landslide-prone zones of West Bengal are Darjeeling and Kalimpong. But, the hilly areas of the Alipurduar and Jalpaiguri districts also face landslides.

The most cyclone-prone areas of West Bengal are North and South 24 Parganas and Purba and Paschim Medinipur districts.

Drought-prone areas of West Bengal are the western plateau and its adjacent regions (Purulia, Bankura, Birbhum, Paschim Bardhaman, Paschim Medinipur and Jhargram districts).

The most flood-prone areas of West Bengal are the Sundarban region, the coastal region of Purba Medinipur, the northern Terai region, and the Rarh plain due to the release of excessive water from barrages and reservoirs.

Cyclones are known by different names in different countries, such as

Cyclone in the Bay of Bengal and the Arabian Sea,

Typhoon in the  China Sea, Taifu in Japan, Hurricane in the West Indies and Caribbean Sea, Willy-Willy in Australia,

Tornados in Mexico and southeast America, Baguio in the Philippines, etc.

Richter Scale is a measuring scale of earthquake intensity.

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Hazards And Disasters Notes For Class 9 WBBSE Geography

In 1935, CF Richter invented the measuring scale of earthquake intensity.

It is not possible to stop a disaster most of the time. However, some measures can be taken to tackle the effects of a disaster to reduce the loss of life and damage to property. Such measures are called disaster management.

Three steps of disaster management are pre-disaster management, during-disaster management, and post-disaster management.

The possibility of loss or damage due to any hazard or disaster is called risk.

While the disaster or hazard intensified, people could not resist and surrender to it. This is called vulnerability.

All the essential materials that are sent to the disaster-affected people are called relief.

Disaster mitigation means the measures that are taken before a disaster to eliminate or reduce the intensity of the damage.

Rehabilitation is a process, which brings back the disaster-affected people into normal life after the disaster.

The three disaster prevention processes are together known as PMR, where

P = Preparedness or preparation,

M = Mitigation or reduction and

R = Recovery or reclamation.

The helper’s group for the quick response or relief and rescue work management is called QRT (Quick Response Team)

DART (Deep Ocean Assessment and Reporting of Tsunami) is a special system for Tsunami alertness.

The act that was enacted in 2005 to deal with the management of disasters is called the Disaster Management Act, 2005.

The full form of UNDMT is the United Nations Disaster Management Team.

The National Flood Commission was formed in 1980.

WBBSE Chapter 5 Weathering Salient Points Introduction

The word weathering has been derived from the word weather.

The term weathering was first used by geologist G. K. Gilbert.

Weathering is a static process, i.e. disintegrated or decomposed rocks do not get removed from their original place.

Erosion is a process whereby weathered materials are transported and deposited elsewhere by various exogenetic forces.

Denudation is the process in which the lower layers of the rocks are exposed through the removal of the upper layers by weathering and erosion.

Without the effect of external or internal forces, the weathered debris of rocks moves downward along the slope due to the gravitational force and is transported and deposited elsewhere. This process is known as mass wasting.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

Mechanical weathering occurs in hot desert areas, polar regions, and high mountain regions.

Exfoliation occurs in homogeneous rocks like granite.

Block disintegration is seen more in basalt.

Granular disintegration is prevalent more in heterogeneous rocks, i.e. rocks formed of various minerals.

The formation of ice crystals is observed more along the foothills of the mountains in cold temperate climatic regions.

Chemical weathering is more active in equatorial and humid-tropical climatic regions.

Water and atmospheric oxygen react with the iron-containing rocks and lead to the formation of rust on them. This process is known as oxidation.

Weathering Notes For Class 9 WBBSE Geography

The process of solution is more active in rocks like chalk, limestone, dolomite, etc.

• Biological weathering is caused by various plants and animals.
• The fragmented rock waste creating a loose covering on the Earth’s surface due to weathering is called regolith.
• The process of soil formation from rock debris is called pedogenesis.
• The smallest particles in the process of soil formation are called the ped.
• Minerals in the upper layers of the soil mix with rainwater and move downwards. This is called leaching and the process is called eluviation. The process of accumulation of these particles in the lower layers is called illuviation.

Humus is a deep black-colored complex matter, formed due to the decomposition of organic matter. Over a long period, soil develops as a result of the mixing of rock wastes, humus, and water.

Terrace farming, contour farming, and strip cropping prevent soil erosion on the slopes of the mountains.

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The process of preventing soil erosion by covering it with a layer of roots of crops, twigs, tendrils, and specks of dust is called mulching.

• Due to changes in temperature and humidity, increase or decrease of pressure on rocks, etc., surface rocks get disintegrated by mechanical action. This process is called mechanical weathering.
• Physical change or change of shape in the. rocks are seen in mechanical weathering but there is no change in the chemical composition or character of the rock-forming minerals.
• The process of granular disintegration causes noises like gunshots.
• Carbonic acid (H₂CO₃) plays an important role in the carbonation process,
  
• The various methods of soil conservation maintain the quality of soil and prevent soil erosion.
  
• Various natural causes of soil erosion are rainfall, winds, sea waves, glaciers, etc,. and human activities responsible for soil erosion are deforestation, unplanned urbanization, the extension of the transportation network, unscientific settlement, etc.
  

The processes of soil erosion due to stream action are sheet erosion, rill erosion, gully erosion, and ravine erosion.

WBBSE Chapter 4 Geomorphic Process And Landforms Of The Earth’s Introduction

The processes that build various new landforms and deform the shapes of landforms are called geomorphic processes or land-building processes

Geomorphic processes are of two types. These are- the terrestrial process and 2 extra-terrestrial processes.

Terrestrial processes are of two types- endogenic or endogenetic processes and 2 exogenic or exogenetic processes.

Endogenic processes are further divided into two divisions- diastrophism movement and 2 sudden movements.

The diastrophic process acts slowly over a long period, It can be of three types- geotectonic movement,2 isostatic movements,s, and 3 eustatic movements.

Geotectonic movements are further subdivided into two groups- Orogenic movement: This movement works almost horizontally or tangentially with the surface. Epeirogenic movement: This movement works vertically with the surface or along the radius of the Earth.

The word ‘petrogenic’ has been derived from the Greek word ‘repairs’ meaning continent and the word ‘orogeny’ has been derived from the Greek word ‘oros’ meaning mountain.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

The process of worldwide simultaneous change of water-holding capacity of the ocean basin due to the rise or fall of the sea level is called eustatic movement.

The tectonic process that helps to maintain elevational balance among various landforms is called isostatic movement.

Sudden movements occur very rapidly due to sudden endogenic forces that originate within the Earth’s interior. Examples of sudden movements are volcanic eruptions and earthquakes.

Processes that operate on the Earth’s surface are known as exogenetic processes. These processes are divided into three divisions- degradation, aggradation, and mass wasting.

The process which is involved with the decrease of elevation of landforms by erosion is called degradation.

The process which is involved with the upliftment or increase of elevation of landforms by deposition is called aggradation.

Gradation is a process of reaching the equilibrium of altitude differences (i.e. level land) through the process of degradation and aggradation.

Without any medium of erosion disintegrated or loose rock materials move downward along the slope of any sloping land due to gravitational force. This process is known as mass wasting.

Extraterrestrial materials are those which originate in outér space. When extraterrestrial materials like comets and meteors strike the Earth’s surface, it causes a change in the shape of the Earth’s surface. This process is known as the extraterrestrial process.

According to the order of relief, landforms can be divided into three types. The first order of relief continent is the ocean. O Second order of relief-mountain, plateau, plain. Third order of relief-erosional and depositional landforms.

Based on the origin, landforms are divided into three groups-mountain, 2 plateaus, and 3 plains.

Rocky regions that extend over vast areas, with an average height of more than 1000 m above sea level, and have peaks are called mountains.

Fold mountains are mainly composed of sedimentary rocks.

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WBBSE Class 9 Geography Chapter 4 Geomorphic Processes Notes

The highest mountain in the Himalayas; the Longest mountain in the world; the Oldest mountain in the world of India, the Ural of Russia, the Great Dividing Range of Australia, the Appalachian mountain of the USA, the Caledonian mountain, etc.

The term ‘plate’ was first used by Canadian geophysicist J Tuzo Wilson.

French scientist Xavier Le Pichon (1968) is called the ‘Father of Plate Tectonic Theory’.

According to the plate tectonic theory, fold mountains are developed along the convergent plate boundary.

Fold mountains are formed by the collision of two plates- The formation of the Himalayan mountain by the collision of Eurasian and Indian plates, and 2 Formation of the Alps mountain by the collision of Eurasian and African plates. Formation of Rocky Mountain by the collision of the North American plate and Pacific Ocean plate. Formation of Andes mountain by the collision of Nazca plate and South American plate.

A cordillera is an extensive chain of mountains or mountain ranges. A belt or group of parallel mountain ranges is known as a cordillera. Example-Rockies, Andes.

• Barren is the only active volcano in India and Narcondam is a dormant volcano of India.
• The highest volcano in the world is Mauna Loa Volcano (9,750 m) on Hawaii Island.
• The Katmai Volcano of Alaska is known as the Valley of Ten Thousand Smokes.
• Fujiyama of Japan and Krakatoa of Indonesia are examples of dormant volcanoes.
• Popa of Myanmar is an extinct volcano.
• In certain places in the mantle, the temperature remains relatively higher than normal conditions due to the presence of radioactive materials and convection currents. These are called hotspots. Tibesti Mountain is located on the top of such a hotspot.
• Due to excessive heat, an upwelling current of magma originates from the hotspots. It is known as a plume.
• Most of the world’s active volcanoes are situated along the margin of the Pacific Oceanic Plate; thus together these volcanoes are called the Pacific Ring of Fire.
• When a block of the landmass is uplifted along a fault as a result of epeirogenic movement, it forms a flat-topped hill called block mountain.

When a block of landmass subsides along two faults as a result of epeirogenic movements, it forms a subsided block known as a rift valley or graben.

• The longest rift valley in the world is the Great Rift Valley (4800 km long) in East Africa.
• Another name for the residual mountain is a relict mountain.
• The residual mountains of India are Aravalli, Mahakal, Mahadev, etc.
• Table like landform which lies around 300 meters above sea level and has an almost flat top with a steep slope, is called a plateau.
• The highest plateau of India is the Ladakh plateau.
• Largest plateau of India is Deccan plateau.
• The continental plateau is also called the shield plateau.
• The stable interior portion of the Earth’s surface is called a craton.

Some important continental plateaus are the Colorado Plateau of the USA, the Africa Plateau, the Canadian Shield, the Greenland Plateau, the Australian Plateau, etc.

• The largest intermontane plateau in the world is the Tibetan Plateau.
• The highest plateau in the world is Pamir. It is also known as the Roof of the Earth.
• Examples of dissected plateaus of India are the Chota Nagpur, Bundelkhand, and Baghelkhand Plateau.
• The Deccan Plateau is an example of a lava plateau. It is composed of alkaline rock like basalt.
• A large expanse of land, having gentle undulations, at sea level or a slightly higher altitude (less than 300 m), is called a plain.
• The largest plain of India is the North Indian Plain which has been formed by the silt of the Ganga-Brahmaputra-Indus River.
• Turan lowland is an example of a subdued plain.
• Siberian Plain is the largest plain in the world.
• The delta plain between the Ganga and the Brahmaputra is the largest deltaic plain in the world.
• The flat plains formed over the eroded uneven topography by the continental ice sheets are called glacial plains.

WBBSE Chapter 3 Determination Of Location Of A Place Of The Earth’s Surface Introduction

In ancient times, by observing the position of the star in the night sky, the latitude was determined. In the northern hemisphere, latitude can be accurately determined with the help of the Pole Star.

During the daytime, the latitude of a place can be determined by the angle of inclination of the Sun,

In the night sky of the southern hemisphere, latitude can be determined by the angle of inclination of Hadley’s Octant.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

Latitude is the angular distance of a place either north or south of the Equator on the equatorial plane.

Nowadays, latitudes are determined with the help of Sextant, Transit theodolite, etc. ‘

The lowest and highest values of latitude are 0° and 90° respectively.

Parallels of latitude are the imaginary lines drawn on the maps and globes, that join all the places having the same latitudinal value.

WBBSE Class 9 Determination of Location Notes

Parallels of latitude are extended in an east-west direction. Amongst them, the circumference of the Equator is the largest. Circumference of latitudes decreases with distance from the Equator to the Poles. The total number of parallels at an interval of 1° is 179 to the north and south of the Equator.

Important parallels are the Equator (0°), Tropic of Cancer 23½ºN, Tropic of Capricorn 23½ºS, Arctic Circle 66½ºN and Antarctic Circle 66½ºS.

The distance between the 1° latitudinal interval on the Earth’s surface is about 111 km or 69 miles.

The climate on the Earth’s surface changes with the change of parallels of latitude. Based on climate change, the Earth is divided into 3 heat belts. They are the Torrid zone, the Temperate zone, and the Frigid zone.

Determination Of Location Of A Place Class 9 WBBSE Summary

The angular distance of a place east or west of the Prime Meridian, which is measured in degrees, minutes, and seconds is known as longitude.

The longitude of the Prime Meridian is 0° and the angular distance of other meridians is imagined to the east as well as to the west of the Prime Meridian upto 180°.

Places with the same longitudinal value are joined by semi-circular lines imagined from the North Pole to the South Pole. Such lines are known as Meridians.

The Prime Meridian (0°) and the 180° meridian, which is the exact opposite side of it, together make a full circle, that divides the Earth into two halves. The eastern half is known as the eastern hemisphere and the western half is the western hemisphere.

All the meridians are equal in length, but not parallel to each other. This is because all meridians meet at the Poles.

Understanding Geographic Coordinates for NEET

There is a 4-minute time difference for a 1° longitudinal difference.

Considering the maximum inclination of the Sun on a longitude passing through a place as noon, the time of that place throughout the day is calculated. This specific time of that place is called its local time.

More than one local time is observed in countries with great east-west extension. Therefore, to avoid multiple local times, a meridian is chosen passing through the central position of the country to calculate the standard time of the whole country.

The Indian Standard Time (IST) is calculated based on the meridian (82°30’E) that extends through Mirzapur of Allahabad.

Greenwich Mean Time (GMT) is determined according to the Prime Meridian (0°) passing through Greenwich. The time of the whole Earth is determined as per Greenwich Mean Time.

The time from midnight to noon of the next day is called ante meridian or am. The time from noon to midnight is called post meridian or pm.

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Key Terms Related to Location Determination for Class 9

If the center of a circle is drawn on the surface of the Earth and the center of the Earth lies at the same point, then the circle is called the Great Circle.

Parallels of latitude and meridians of longitude intersect each other and form a network, that is called Earth’s grid.

There are two ends of any diameter of the spherical Earth, where one end is the antipode to the other.

A place and its antipode always lie in opposite hemispheres. This is why the difference in longitude and local time between these two places is 180° and 12 hours respectively.

The International Date Line has been imagined through the middle of the Pacific Ocean roughly following the 180° meridian.

The Latitudes and longitudes are measured in degrees(), minutes(‘), and seconds(“). Time is calculated in hours (hrs), minutes (mins), and seconds (secs).

For every 1° longitudinal difference, the time difference is 4 minutes. For every 1′, longitudinal difference, the time difference is 4 seconds.

Concerning the measurement of latitude and longitude: 1°= 60′ and 1′ = 60″.Concerning time calculation: 1h = 60m and 1m = 60s.

GMT refers to Greenwich Mean Time (0° meridian) and IST refers to Indian Standard Time (82½º E meridian).

We move ahead in time as we move from east to west.

While calculating total time, if the time required to deliver a message is mentioned, that time is to be added at the end. On the other hand, while calculating longitude, that extra time is to be subtracted from the total time.

Steps to calculate time based on longitudinal difference—

The first step is to find out the longitudinal difference between the two given places. If both the places are located in the same hemisphere, then the longitude with a smaller value is to be subtracted from the longitude with a larger value. If both the places are located in different hemispheres, then the value of both longitudes is to be added.

The next step is to find out the time difference referring to the fact that, for every 1° longitudinal difference, the time difference is 4 minutes.

The position of the longitude whose time is to be calculated is to be found out concerning the other longitude.

If the place, for which time needs to be determined is to the east, the difference in time is to be added. On the other hand, if the place, for which time needs to be determined, is to the west, the difference in time is to be subtracted.

Steps to calculate longitude based on the time difference—

The first step is to find out the difference in time between the two given places.

The next step is to find out the longitudinal difference by dividing the value of the time difference by 4.

If the time of the place, whose longitude is to be determined, is ahead of that of the other place, then the former is located to the east of the latter. Whereas, if the time of the place, whose longitude is to be determined, is behind that of the other place, then the former is located to the west of the latter.

If the place for which time needs to be determined is in the east, the difference in longitude is to be added and if in the west, the difference in longitude is to be subtracted.

The time difference between a place and its antipode is 12 hours and the longitudinal difference between a place and its antipode is 180°.

WBBSE Chapter 2 Movements Of The Earth Salient Points Introduction

Every planet in the solar system rotates on its axis and revolves around the Sun.

The speed of rotation of Venus is less than the other planets of the solar system (equal to 243 Earth days).

The main statement of the Geocentric Theory is that the Sun and the planets are moving around the Earth. Although, now this concept has been proved wrong.

According to the Heliocentric Theory, the planets are moving around the Sun.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

The main proponents of Heliocentric Theory were Nicolaus Copernicus, Galileo, and Kepler.

In 1687, Sir Isaac Newton proved by his law of gravity that the Earth has two. motions-rotation and revolution, which are in action simultaneously.

The average distance of the Earth from the Sun is 150 million km.

Understanding Earth’s Rotation and Revolution

In 1851, Leon Foucault, a French physicist, demonstrated an experiment at Pantheon Church in Paris, France to prove the rotation of the Earth.

The speed of the Earth’s rotation is different at the different latitudes, 1675 km/hr at the Equator, 1533 km/hr at the Tropic of Cancer and Capricorn, 666 km/hr at both the Arctic and Antarctic Circle, and 0 km/ hr at the two Poles.

In 1835, GD Coriolis, a French mathematician first proved that the rotation of the Earth is responsible for the generation of a centrifugal force which is known as the Coriolis force.

WBBSE Class 9 Movements of the Earth Notes

Under the influence of centrifugal force due to the rotation of the Earth, the ocean currents and planetary winds deflect from their direction in both hemispheres, which is known as Ferrel’s law.

The circumference of the Earth’s orbit is 960 million km.

The axis of the Earth is an imaginary line. that joins the North and the South Poles and passes through the center of the Earth.

The Earth’s axis remains permanently tilted at an angle of 66 to the Earth’s orbital plane.

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Movements Of The Earth Class 9 WBBSE Geography Summary

The phenomenon of equal lengths of day and night all over the Earth is called equinox. The days and nights are of equal duration everywhere on Earth on 21 March and 23 September. These days are called vernal equinox in the northern hemisphere and autumnal equinox in the southern hemisphere respectively.

On 21 June, sunrays fall vertically over the Tropic of Cancer, and the day is called the summer solstice.

On 22 December, sunrays fall vertically over the Tropic of Capricorn, and the day is called the winter solstice.

The average velocity of the Earth’s revolution is 30km/sec.

Key Terms Related to Earth’s Movements for Class 9

Aurora in the north polar region and the south polar region is known as Aurora Borealis and Aurora Australis respectively.

The Earth is farthest from the Sun (approximately 152 million km) on July 4. This phenomenon is called Aphelion.

The Earth is closest to the Sun (approximately 147 million km) on January 3. This phenomenon is called Perihelion. Movements of the Earth

The apparent movements of the Sun are of two types, namely Apparent diurnal movement and 2 Apparent annual movements of the Sun.

Every day, we get to see the Sun rises in the east and set in the west. This is called the apparent diurnal movement of the Sun.

All through the year, it seems that the Sun moves between the Tropic of Cancer and the Tropic of Capricorn. This is known as the apparent annual movement of the Sun.

The apparent path of the Sun throughout the year is known as the ecliptic.

WBBSE Chapter 1 Earth As A Planet Salient Points Introduction

In ancient times, people thought that the Earth was flat and in Greek civilisation people considered that the Earth was flat and rounded as a disc.

According to Greek scholar Anaximander, the Earth was a floating disc in the ocean surrounded by a round sky.

The Portuguese globetrotter Ferdinand Magellan provided the first direct evidence in favour of the concept that ‘the Earth is round’.

Earth appears blue from space because water bodies cover 71% of the Earth’s surface.

Read and Learn Also WBBSE Class 9 Geography And Environment Notes

Greek philosopher, Aristotle stated the concept of the Earth being a sphere by observing the relative position of the stars and the shadow of the Earth that falls on the Moon during a lunar eclipse.

To prove the spherical shape of the Earth, the Bedford Level experiment was conducted in 1870.

The boundary where the sky seems to meet the ground or the sea is known as the horizon.

A spherical object flattened at the top and bottom (north-south) and bulged out at the middle or centre (east-west) is an oblate spheroid.

WBBSE Class 9 Earth as a Planet Notes

The equatorial and polar diameters of the Earth are 12757km and 12714km respectively.

On the Earth’s surface, the gravitational force is lowest at the Equator and maximum at the Poles.

Scientist Henry Cavendish first determined the Earth’s weight.

Geoid means—like the Earth or the shape of the Earth is like the Earth itself.

Key Terms Related to Earth in Geography

Johann Benedict Listing was the first person to use the word ‘geoid’.

The Science related to measuring the shape of the Earth is called Geodesy.

IAU (International Astronomical Union) listed Pluto as a dwarf planet in 2006.

In ancient days, the distance measurement unit used in Greece was called stadia. 1 stadia = 185 metres.

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Earth As A Planet Class 9 WBBSE Geography Summary

The Pole Star’s angle of elevation is 90° at the North Pole and 0° at the Equator i.e. the Pole Star is visible at the horizon in the Equator.

The light of the Sun takes 8.2 minutes to reach the Earth.

The area of the Earth’s surface is about 510 million sq. km.

The actual circumference of the Earth is about 40075km.

Examples of Earth’s Habitable Conditions

The South Pole of the Earth is about 20 m flat.

The average temperature of the Earth is about 15°C.

The average density of the Earth is 5.515 grams/cubic centimetre.

The full form of GPS is the Global Positioning System. GPS helps to know the exact or correct location of any place on the Earth’s surface.