Class 7 Geography

WBBSE Class 7 Geography Chapter 7 Water Pollution Notes

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WBBSE Class 7 Geography Chapter 7 Water Pollution Introduction

197 percent of the water on Earth is saline seawater, 2 percent is trapped in ice caps and only 1 percent remains in the rivers, lakes, underground aquifers, and other fresh water bodies. Water pollution occurs when any chemical or organic substances, toxic substances or germs are mixed in the water due to different indiscriminate human activities and various natural causes and the water becomes unfit for humans and other animals to use.

When the used, warm and contaminated wastewater from thermal power stations, nuclear power plants, and factories mix directly in the ponds or rivers reducing the oxygen level of those waterbodies, thermal pollution occurs. As a result of the uncontrolled extraction of excess groundwater, arsenic compounds react with air to form toxic metallic compounds. These compounds contaminating water, are called arsenic contaminators.

Radioactive substances used in nuclear reactors, medical centers or scientific laboratories are dumped into the sea or river after use. This causes radioactive pollution. Wastewater from agricultural fields rich in nitrates, phosphates, and sulphates are carried to nearby ponds, lakes, rivers, etc.

As a result, the nutrient level of the water bodies increases, which promotes the excessive growth of algae, weeds, and water hyacinths, and subsequently aquatic animals die due to reduced levels of dissolved oxygen. This phenomenon is called eutrophication. In 1932, liquid waste containing methylmercury from a chemical factory off the coast of Minamata Bay in Japan was discharged into the sea. This methyl mercury got deposited in the body of marine fishes.

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WBBSE Class 7 Geography Chapter 7 Water Pollution Notes

Later, the inhabitants of the coast became infected with incurable diseases (deaths and disabilities) as a result of eating these fishes. This mercury poisoning is known as Minamata disease. When high doses of arsenic enter the human body through drinking water and food, it causes black sores on the palms of hands and soles of feet. It is known as Blackfoot disease.

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When high doses of cadmium enter the human body through drinking water and food, the bones of the human body become brittle and cause intolerable pain. It is called Itai-Itai disease. Fluoride contamination causes problems in human teeth and bones. It is known as fluorosis disease. It is a disease caused by calcium deficiency. Waterborne infection can be prevented by drinking pure water, maintaining general rules of cleanliness, using lavatories, and disposing of garbage at the proper place.

Water can be purified in various ways, such as boiling water for 10 minutes at 100°C temperature, covering the turbid water for some hours so that most of the filthy things can be deposited at the bottom, mixing adequate amounts of chlorine with water, etc. A severe shortage of water all over the world can be compensated by the prevention of water pollution as well as minimizing excessive use of water and reusing it to the maximum capacity

WBBSE Class 7 Geography Chapter 7 Water Pollution Multiple Choice Questions

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WBBSE Chapter 7 Water Pollution Multiple Choice Questions

Question 1. Of the total water on the Earth’s surface, about 97% is-

  1. River water
  2. Tubewell water
  3. Ocean water

Answer: 3. Ocean water

Question 2. Of the total water of the Earth’s surface, the percentage of fresh water is-

  1. 3%
  2. 15%
  3. 90%

Answer: 1. 3%

Question 3. The percentage of the Earth’s surface covered with water is-

  1. 43
  2. 71
  3. 13

Answer: 2. 71

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Question 4. The percentage of fresh water in rivers and lakes is-

  1. 1
  2. 2
  3. 5

Answer: 1. 1

WBBSE Class 7 Geography Chapter 7 Water Pollution Multiple Choice Questions

Question 5. _______contributes the most to water pollution.

  1. Thermal power plants
  2. Leather industry
  3. Paper industry

Answer: 1. Thermal power plants

Question 6. Which of the following industry is a major contributor to water pollution?

  1. Cotton textile
  2. Electronics
  3. Paper and leather

Answer: 3. Paper and leather

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Question 7. In developed countries, water pollution is mainly caused by-

  1. Acid rain
  2. Basic rain
  3. Excreta of humans and domestic animals

Answer: 1. Acid rain

Question 8. In developing countries, water pollution is mainly caused by waste products of-

  1. Humans and animals
  2. Industrial by-products and wastes
  3. Atomic power stations

Answer: 2. Industrial by-products and wastes

Question 9. The metal which causes maximum water pollution is-

  1. Lead and mercury
  2. Iron and copper
  3. Sodium

Answer: 1. Lead and mercury

Question 10. What is grown to control chemical pollution in water?

  1. Water hyacinth
  2. Algae
  3. Lotus

Answer: 1. Water hyacinth

Question 11. Oil spills cause water pollution, mainly by –

  1. Forming a layer of oil on the water surface
  2. Helping in the transfer of atmospheric oxygen to the water
  3. Changing the chemical nature of water

Answer: 1. Forming a layer of oil on the water surface

Question 12. Eutrophication leads to an increase in the amount of-

  1. Algae
  2. Moss in water
  3. Mushroom

Answer: 1. Algae

Question 13. In the waterbody, eutrophication is caused as a response to the-

  1. Increased nutrient levels
  2. Increased oxygen level
  3. Decreased oxygen demand

Answer: 2. Increased oxygen level

Question 14. Arsenic is a type of-

  1. Water Pollutant
  2. Air Pollutant
  3. Land Pollutant

Answer: 1. Water Pollutant

Question 15. Amoebiasis is a waterborne disease caused by-

  1. Protozoa
  2. Bacteria
  3. Virus

Answer: 1. Protozoa

Question 16. Black patches are seen on the soles of the feet of humans as an effect of-

  1. Mercury
  2. Arsenic
  3. Cadmium

Answer: 2. Arsenic

Question 17. A waterborne disease caused by bacteria is-

  1. Cholera
  2. Hepatitis A
  3. Tuberculosis

Answer: 1. Cholera

Question 18. A protozoan called Entamoeba Histolytica causes-

  1. Hepatitis A
  2. Amoebiasis
  3. Typhoid

Answer: 2. Amoebiasis

Question 19. Itai-Itai or Ouch Ouch disease is caused by-

  1. Mercury
  2. Arsenic Poisoning
  3. Cadmium

Answer: 3. Cadmium

Question 20. The effect of arsenic is observed in which district of West Bengal?

  1. Birbhum
  2. Nadia
  3. Jalpaiguri

Answer: 2. Nadia

Question 21. Hepatitis A is a disease that is borne by-

  1. Air
  2. Water
  3. Soil

Answer: 2. Water

Question 22. Fluoride is a type of-

  1. Useless Gas
  2. Useful Gas
  3. Harmful Salt

Answer: 3. Harmful Salt

Question 23. The enamel of teeth becomes pitted, rough, and hard to clean due to-

  1. Chlorosis
  2. Arsenicosis
  3. Fluorosis

Answer: 3. Fluorosis

Question 24. _______ is highly affected by arsenic contamination in water.

  1. United Kingdom
  2. India
  3. Iran

Answer: 2. India

Question 25. The bacteria that causes _______ looks like the punctuation mark ‘comma’.

  1. Typhoid
  2. Tuberculosis
  3. Cholera

Answer: 3. Cholera

Question 26. Softening of bones is caused in humans as an effect of-

  1. Minamata
  2. Itai-Itai
  3. Blackfoot

Answer: 2. Itai-Itai

Question 27. When we boil water, the level of arsenic content-

  1. Increases
  2. Decreases
  3. Remains the same

Answer: 2. Decreases

Question 28. Drinking boiled water is-

  1. Safe
  2. Harmful
  3. Unnecessary

Answer: 1. Safe

Question 29. Cholera is a disease borne by-

  1. Air
  2. Soil
  3. Water

Answer: 3. Water

Question 30. The skin disease caused due to the effect of arsenic poisoning is-

  1. Silicosis
  2. Melanosis
  3. Dyslexia

Answer: 2. Melanosis

Question 31. A disease caused by mercury poisoning is-

  1. Minamata
  2. Cholera
  3. Itai-Itai

Answer: 1. Minamata

Question 32. A waterborne disease caused by virus is-

  1. Polio
  2. Typhoid
  3. Amoebiasis

Answer: 1. Polio

Question 33. A waterborne disease caused by bacteria is-

  1. Typhoid
  2. Polio
  3. Amoebiasis

Answer: 1. Typhoid

Question 34. Excessive use of nitrate in agriculture causes-

  1. Jaundice
  2. Dysentery
  3. Cancer

Answer: 3. Cancer

Question 35. An increase in level of BOD indicates-

  1. Higher levels of water pollution
  2. The lower level of water pollution
  3. Higher levels of air pollution

Answer: 1. Higher level of water pollution

Question 36. BOD is a measure of the amount of _______ needed by microorganisms for the oxidation of organic matter.

  1. Carbon dioxide
  2. Oxygen
  3. Hydrogen

Answer: 2. Oxygen

Question 37. Which of the following are arsenic-tolerant plants?

  1. Banana and papaya
  2. Bean and tomato
  3. Paddy and wheat

Answer: 2. Bean and tomato

Question 38. The type of paddy in which arsenic level is high is-

  1. Aus
  2. Aman
  3. Boro

Answer: 3. Boro

Question 39. During the Gulf War which waterbody was polluted?

  1. Bay of Bengal
  2. Mexican Gulf
  3. Persian Gulf

Answer: 3. Persian Gulf

Question 40. Thermal pollution mainly changes the-

  1. Chemical properties of water
  2. Ecosystem composition of water
  3. Number of organisms in the water

Answer: 2. Ecosystem composition of water

Question 41. After the establishment of Haldia Petrochemicals, number of Hilsa fish has conspicuously decreased at the mouth of-

  1. Ajay river
  2. Teesta river
  3. Haldi river

Answer: 3. Haldi River

Question 42. The states of India which are highly affected by arsenic poisoning are-

  1. West Bengal, Bihar
  2. Uttar Pradesh, Haryana
  3. Maharashtra, Tamil Nadu

Answer: 1. West Bengal, Bihar

Question 43. The pH value of pure water is-

  1. 7
  2. 3
  3. 9

Answer: 1. 7

Question 44. A pesticide used to kill birds and rodents is-

  1. Atropine
  2. Strychnine
  3. Morphine

Answer: 2. Strychnine

Question 45. According to WHO, the number of children die every year due to waterborne diseases are-

  1. 30 million
  2. 40 million
  3. 50 million

Answer: 1. 30 million

Question 46. A person in the USA uses more than ________ liters of water daily.

  1. 50
  2. 70
  3. 80

Answer: 1. 50

WBBSE Class 7 Geography Chapter 5 River Multiple Choice Questions

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WBBSE Class 7 Geography Chapter 5 MCQs

WBBSE Chapter 5 River Multiple Choice Questions

Question 1. Gangotri Glacier is the source of the river-

  1. Ganga
  2. Yamuna
  3. Tista

Answer: 1. Ganga

Question 2. The place where a river joins a sea, ocean or any other waterbody is called its-

  1. Source
  2. Mouth
  3. Obasin

Answer: 2. Mouth

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Question 3. The mouth of Ganga is in the-

  1. Bay of Bengal
  2. Indian Ocean
  3. Arabian sea

Answer: 1. Bay of Bengal

Question 4. The landform that distributes rainwater in opposite directions is-

  1. Catchment area
  2. River Valley
  3. Watershed

Answer: 3. Watershed

WBBSE Class 7 Geography Chapter 5 MCQs

Question 5. is an important tributary of River Ganga.

  1. Bhagirathi
  2. Yamuna
  3. Hoogly

Answer: 2. Yamuna

WBBSE Class 7 Geography Chapter 5 River Multiple Choice Questions

Question 6. Distributaries are found in the-

  1. The upper course of a river
  2. The middle course of a river
  3. The lower course of a river

Answer: 1. Lower course of a river

Question 7. Luni is an inland river of –

  1. India
  2. Russia
  3. China

Answer: 1. India

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Question 8. The rivers of the mountainous areas have

  1. Only in winter
  2. Only in summer
  3. Throughout the year

Answer: 3. Throughout the year

WBBSE Class 7 Geography Chapter 5 MCQs

Question 9. On a map, non-perennial rivers are shown in-

  1. Red colour
  2. Brown colour
  3. Black colour

Answer: 3. Black colour

Question 10. Ichamati is a-

  1. Rain-fed river
  2. Tide-fed river
  3. Snow-fed river

Answer: 2. Tide-fed river

Question 11. Godavari is a-

  1. Rain-fed river
  2. Tide-fed river
  3. Snow-fed river

Answer: 1. Rain-fed river

Question 12. Famous cities are situated in the Ganga Yamuna Doab region of-

  1. Agra and Allahabad
  2. Bengaluru and Secunderabad
  3. Chandigarh and Amritsar

Answer: 1. Agra and Allahabad

Question 13. When the energy of the river decreases, it ___________ its load.

  1. Deposits
  2. Transports
  3. Erodes

Answer: 1. Deposits

Question 14. The main work of a river in its upper course is-

  1. Deposition
  2. Erosion
  3. Transportation

Answer: 2. Erosion

West Bengal Class 7 Geography Chapter 5 Multiple Choice Questions

Question 15. In the mountain stage, the velocity of the river is-

  1. High
  2. Low
  3. Moderate

Answer: 1. High

Question 16. ‘I’ shaped valleys are formed by rivers in their-

  1. Mountain Stage
  2. Plain Stage
  3. Delta Stage

Answer: 1. Mountain Stage

Question 17. A narrow and deep valley is carved by a river in a-

  1. Humid region
  2. Plain region
  3. Arid region

Answer: 1. Humid region

Question 18. ___________ is a feature formed by a river in its upper course.

  1. Delta
  2. Floodplain
  3. Canyon

Answer: 3. Canyon

West Bengal Class 7 Geography Chapter 5 Multiple Choice Questions

Question 19. A very deep river valley is called a-

  1. Gorge
  2. Pothole
  3. Waterfall

Answer: 1. Gorge

Question 20. The stretch between Gomukh ice cave near Gangotri Glacier and Haridwar is identified as the-

  1. The upper course of river Ganga
  2. The middle course of river Ganga
  3. The lower course of river Ganga

Answer: 1. Upper course of river Ganga

Question 21. The mountain stage of a river is similar to the life of a man in his-

  1. Youth
  2. Old age
  3. Matured stage

Answer: 1. Youth

Question 22. Potholes are formed by a river in its-

  1. Mountain stage
  2. Delta stage
  3. Plain stage

Answer: 1. Mountain stage

Question 23. In the plain stage, a river forms ___________.

  1. Waterfalls
  2. River islands
  3. Potholes

Answer: 2. River islands

Class 7 Geography Chapter 5 MCQs WBBSE 

Question 24. Is a feature formed by a river in its middle course.

  1. Gorge
  2. Ox-bow lake
  3. Delta

Answer: 2. Ox-bow lake

Question 25. The main work of a river in its lower course is –

  1. Erosion
  2. Deposition
  3. Transportation

Answer: 2. Deposition

Question 26. Natural levees are formed by rivers in their-

  1. Lower course
  2. Upper course
  3. Middle course

Answer: 1. Lower course

Question 27. Floodplains are formed by rivers in their-

  1. Middle course
  2. Upper course
  3. Lower course

Answer: 3. Lower course

Class 7 Geography Chapter 5 MCQs WBBSE 

Question 28. A delta is formed by a river in its-

  1. Lower course
  2. Upper course
  3. Middle course

Answer: 1. Lower course

Question 29. The lower course of a river is similar to the life of a man in his-

  1. Old age
  2. Youth
  3. Matured stage

Answer: 1. Old age

Question 30. The course of an ideal river can be divided into-

  1. 1 stage
  2. 3 stages
  3. 4 stages

Answer: 2. 3 stages

Question 31. The longest estuary in the world is located at the mouth of the River-

  1. Amazon
  2. Padma
  3. Ob

Answer: 3. Ob

Question 32. Some rivers flow at a high speed in their lower course due to the presence of-

  1. Delta
  2. Doab
  3. Estuary

Answer: 3. Estuary

WBBSE Geography Chapter 5 MCQs for Class 7

Question 33. Suspension is a process of river-

  1. Erosion
  2. Deposition
  3. Transportation

Answer: 3. Transportation

Question 34. Saltation and traction are rivers-

  1. Erosion processes
  2. Transportation processes
  3. Deposition processes

Answer: 2. Transportation processes

Question 35. Attrition is a process of the river-

  1. Erosion
  2. Deposition
  3. Transportation

Answer: 1. Erosion

WBBSE Class 7 Geography Chapter 6 Rock And Soil Notes 

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WBBSE Class 7 Geography Chapter 6 Rock And Soil Introduction

A mineral is a naturally-occurring inorganic substance that consists of one or more elements to form a rock. Rock are naturally formed aggregates made up of one or more minerals. In other words, all components that made up the Earth’s solid crust are called rocks.

For millions of years, various natural forces have acted on the rocks. As a result disintegrated finer particles are formed. These are called regolith. This regolith mixes with organic matter (formed by the decomposition of dead plants and animals) and forms a thin and soft layer, which is conducive to plant growth, on the Earth’s crust. This layer is called soil.

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Volcanic eruptions of magma accumulate on the Earth’s surface or beneath the Earth’s surface and then gradually cool down and harden to form igneous rocks. The igneous rocks get disintegrated by the action of different natural agents and are subsequently deposited in layers on the sea bed.

WBBSE Class 7 Geography Chapter 6 Rock And Soil Notes

With the passage of time, after being subjected to high pressure and temperature, these layers of sediments undergo solidification to form hard rocks called sedimentary rocks. Under high temperatures and great pressure, a pre-existing igneous or sedimentary rock may change into a new form which is of rock called metamorphic rock. These rocks are hard and resistant to erosion.

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The soil that contains a high amount of sand and is not suitable for agriculture is called sandy soil. The soil that contains an equal amount of sand and silt and a little amount of clay and is ideal for agriculture is known as loamy soil. The soil that has a high amount of clay particles and has high water-holding capacity is known as clayey soil.

For millions of years, various physical, chemical and organic processes have acted on the rocks thereby disintegrating them into smaller fragments. These fragments after that formed a loose, unconsolidated layer on the Earth’s surface called regolith. Soil is actually formed from regolith.

WBBSE Class 7 Geography Chapter 6 Rock And Soil Multiple Choice Questions 

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WBBSE Class 7 Geography Chapter 6 Rock And Soil Multiple Choice Questions

Question 1. Which of the following is an important rock-forming mineral?

  1. Dolerite
  2. Quartz
  3. Conglomerate

Answer: 2. Quartz

Question 2. Stones laid on railway tracks are ________ rocks.

  1. Igneous
  2. Metamorphic
  3. Sedimentary

Answer: 1. Igneous

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Question 3. Which of the following is a source of mineral oil?

  1. Sedimentary rock
  2. Igneous rock
  3. Metamorphic rock

Answer: 1. Sedimentary rock

WBBSE Class 7 Geography Chapter 6 Rock And Soil Multiple Choice Questions

Question 4. Baking soda and alum belong to which of the following category?

  1. Minerals
  2. Rocks
  3. Soil

Answer: 1. Minerals

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Question 5. Layers or strata are found in-

  1. Sedimentary rocks
  2. Igneous rocks
  3. Metamorphic rocks

Answer: 1. Sedimentary rocks

Question 6. An example of primary rock is-

  1. Granite
  2. Sandstone
  3. Shale

Answer: 1. Granite

Question 7. An example of igneous rock is-

  1. Sandstone
  2. Basalt
  3. Quartzite

Answer: 2. Basalt

Question 8. Igneous rocks are also called-

  1. Stratified rocks
  2. Non-stratified rock
  3. Altered rocks

Answer: 2. Non-stratified rock

Question 9. What percentage of the Earth’s crust is composed of igneous rocks?

  1. 60%
  2. 80%
  3. 90%

Answer: 2. 80%

Question 10. Granite is metamorphosed into-

  1. Gneiss
  2. Marble
  3. Hornblende

Answer: 1. Gneiss

Question 11. Himalayas are formed of-

  1. Igneous rocks
  2. Sedimentary rocks
  3. Igneous and sedimentary rocks

Answer: 3. Igneous and sedimentary rocks

Question 12. Which of the following rocks are also called primary rocks?

  1. Igneous rocks
  2. Sedimentary rocks
  3. Metamorphic rocks

Answer: 1. Igneous rocks

Question 13. Granite is an example of-

  1. Igneous rock
  2. Metamorphic rock
  3. Sedimentary rock

Answer: 1. Igneous rocks

Question 14. Large deposits of granite are found in the-

  1. Himalayas
  2. Lava plateau of Maharashtra
  3. Chotanagpur Plateau of Jharkhand

Answer: 3. Chotanagpur Plateau of Jharkhand

Question 15. Due to the very high temperatures in the Earth’s interior, all materials are found in a-

  1. Gaseous state
  2. Viscous state
  3. Solid state

Answer: 2. Viscous state

Question 16. A sedimentary rock formed from dead organic matter is-

  1. Coal
  2. Gneiss
  3. Mudstone

Answer: 1. Coal

Question 17. Sandstone is metamorphosed into-

  1. Gneiss
  2. Quartzite
  3. Marble

Answer: 2. Quartzite

Question 18. The rock which is used for grinding spices is-

  1. Mudstone
  2. Limestone
  3. Sandstone

Answer: 3. Sandstone

Question 19. The conglomerate is an example of-

  1. Igneous rock
  2. Sedimentary rock
  3. Metamorphic rock

Answer: 2. Sedimentary rock

Question 20. An example of sedimentary rock is-

  1. Granite
  2. Slate
  3. Sandstone

Answer: 3. Sandstone

Question 21. Which of the following is an example of organic rock?

  1. Limestone
  2. Mudstone
  3. Sandstone

Answer: 1. Limestone

Question 22. Ancient monuments and palaces are made from-

  1. Igneous rocks
  2. Sedimentary rocks
  3. Metamorphic rocks

Answer: 2. Sedimentary rocks

Question 23. A sedimentary rock used to light fire is-

  1. Coal
  2. Clay
  3. Sandstone

Answer: 1. Coal

Question 24. A rock useful in the iron and steel industry is-

  1. Limestone
  2. Marble
  3. Basalt

Answer: 1. Limestone

Question 25. Formation of _____ rocks involves a tremendous amount of heat and pressure.

  1. Igneous
  2. Sedimentary
  3. Metamorphic

Answer: 3. Metamorphic

Question 26. The metamorphosed form of coal is-

  1. Graphite
  2. Slate
  3. Gneiss

Answer: 1. Graphite

Question 27. The metamorphosed form of gneiss is-

  1. Schist
  2. Phyllite
  3. Slate

Answer: 1. Schist

Question 28. Sculptures are made from-

  1. Marble
  2. Basalt
  3. Mudstone

Answer: 1. Marble

Question 29. The metamorphosed form of sandstone is-

  1. Quartzite
  2. Gneiss
  3. Slate

Answer: 1. Quartzite

Question 30. The metamorphosed form of gabbro is-

  1. Gneiss
  2. Serpentine
  3. Hornblende

Answer: 2. Serpentine

Question 31. The metamorphosed form of basalt is-

  1. Amphibolite
  2. Hornblende
  3. Gneiss

Answer: 1. Amphibolite

Question 32. Slate is metamorphosed into-

  1. Marble
  2. Phyllite
  3. Gneiss

Answer: 2. Phyllite

Question 33. Mudstone is metamorphosed into-

  1. Slate
  2. Marble
  3. Gneiss

Answer: 1. Slate

Question 34. Fossils are found in-

  1. Igneous rocks
  2. Sedimentary rocks
  3. Metamorphic rocks

Answer: 2. Sedimentary rocks

Question 35. The loose layer of rock debris formed by weathering is called-

  1. Regosol
  2. Raxysol
  3. Regolith

Answer: 3. Regolith

Question 36. Regur soil is formed from the rock called-

  1. Basalt
  2. Granite
  3. Gabbro

Answer: 1. Basalt

Question 37. An inorganic component of the environment is-

  1. Man
  2. Soil
  3. Bacteria

Answer: 2. Soil

Question 38. The percentage of air in the soil is-

  1. 20
  2. 15
  3. 25

Answer: 3. 25

Question 39. In soil, which two components are in equal proportions?

  1. Water-air
  2. Water-organic matter
  3. Air-minerals

Answer: 1. Water-air

Question 40. What is the percentage of organic matter in soil?

  1. 5%
  2. 10%
  3. 15%

Answer: 1. 5%

Question 41. One of the factors controlling the formation of soil is-

  1. Climate
  2. Flow of river
  3. Agricultural activities

Answer: 1. Climate

Question 42. Fertility of soil can be maintained over a long period of time by-

  1. Using chemical fertilisers
  2. Using organic fertilisers
  3. Afforestation

Answer: 2. Using organic fertilisers

Question 43. The water-holding capacity of sandy soil is-

  1. High
  2. Medium
  3. Low

Answer: 3. Low

Question 44. Watermelon is cultivated in-

  1. Sandy soil
  2. Loamy soil
  3. Clayey soil

Answer: 1. Sandy soil

Question 45. Nutrients required for plants are less in-

  1. Sandy soil
  2. Clayey soil
  3. Loamy soil

Answer: 1. Sandy soil

Question 46. The percentage of clay in clayey soil is-

  1. 40-50
  2. 60-70
  3. 80

Answer: 1. 40-50

Question 47. The water-holding capacity is very high in the case of-

  1. Alluvial soil
  2. Sandy soil
  3. Clayey soil

Answer: 3. Clayey soil

Question 48. Aeration in clayey soil is-

  1. Very high
  2. Very less
  3. Medium

Answer: 2. Very less

Question 49. The type of soil used in the cement industry is-

  1. Sandy soil
  2. Loamy soil
  3. Clayey soil

Answer: 3. Clayey soil

Question 50. The space between soil particles is very less in-

  1. Loamy soil
  2. Sandy soil
  3. Clayey soil

Answer: 3. Clayey soil

Question 51. The water-holding capacity of a clayey soil is-

  1. High
  2. Low
  3. Medium

Answer: 1. High

Question 52. The water-holding capacity of loamy soil is-

  1. Medium
  2. Low
  3. High

Answer: 1. Medium

Question 53. The soil preferred by farmers for cultivation is-

  1. Loamy soil
  2. Sandy soil
  3. Clayey soil

Answer: 1. Loamy soil

Question 54. Near river banks, we find-

  1. Alluvial soil
  2. Igneous rock
  3. Sedimentary rock

Answer: 1. Alluvial soil

Question 55. Alluvial soil can be further categorised into-

  1. Three groups
  2. Four groups
  3. Five groups

Answer: 1. Three groups

Question 56. Which of the following trees grow on saline soil?

  1. Betel Nut
  2. Mango
  3. Sundari

Answer: 3. Sundari

Question 57. Mangrove forest is found in coastal-

  1. Saline soil
  2. Alluvial soil
  3. Laterite soil

Answer: 1. Saline soil

WBBSE Class 7 Geography Chapter 5 River Notes

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WBBSE Class 7 Geography Chapter 5 River Introduction

Usually, mountains and plateaus or other highlands from where a river originates is called the source of the river.

  • The place where a river joins a sea, lake or any other water body or the place where the course of the river ends is known as its mouth.
  • The extensive area over which several small streams or channels and the main river flow is called the catchment area of the river. These numerous small streams originate from the highlands and join to form a river at the foothills.
  • The highland which separates the basin of one river system from another is called the watershed or water divide.
  • The peak of the highland divides and distributes the rainwater and makes parts of it flow in different directions.

Read And Learn Also WBBSE Class 7 Geography Notes

Tributaries are called small streams or rivers that flow from different source regions and join the main river.

  • Small streams that branch off the main river channel, flow independently, and have their mouths somewhere else are called distributaries.
  • A river valley is a valley confined by lateral banks through which a river drains from its source to its mouth.
  • The total surface area covered by a river, its tributaries and distributaries, from the source to its mouth is known as the river basin.
  • A river originating in a highland or a lake and emptying itself into a lake or any water body or swamp within the same country is called an inland river.
  • A perennial river is a stream or river that has a continuous flow of water in its channel throughout the year.
  • The streams have their sources high up in the mountains and are generally fed by ice-melt water.
  • A non-perennial river is a river that does not have a continuous flow of water throughout the year, except in the rainy season. These rivers have their sources in a lower land like a plateau and are rain-fed.

WBBSE Class 7 Geography Chapter 5 River Notes

In humid regions, a steep and narrow ‘V-shaped river valley is known as a gorge.

  1. In arid and semi-arid regions, a very steep and narrow ‘T’ shaped valley is known as a canyon.
  2. When landforms formed of resistant and soft rocks lie in the course of a river, arranged in alternate layers, the soft rocks are eroded more and faster due to river action than the resistant rocks.

This results in the creation of a step-like structure, from over which the river water seems to plunge down a certain height. This is known as a waterfall.

  • In the middle course of a river, due to a sudden decrease of the slope of the land and higher discharge of water, the river moves in a sinuous track. This zigzag course is known as a meander.
  • the River deposits the transported sand, silt, etc. on its bed in this middle course because of the reduction in the carrying capacity due to the gentle slope of the land. This load accumulates on the river bed to form a riverine island.
  • In the middle course of a river, there is continuous erosion on one side and deposition on the other side of the sinuous river bends. At times, the river meanders to such an extent, or if the water flow increases, a loop of the meander gets separated from the main channel.

 

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This abandoned channel of the river is known as an oxbow lake or a horse-shoe lake, as it resembles the foot of a horse in shape.

  • In the lower course of the river during floods, the river overflows its banks and deposits fine silt particles of the river bed on the low-lying areas along the channel and further away. As a result, a fertile plain is formed and it is known as a floodplain.
  • When the sand, silt and clay get deposited at the mouth of a river, a triangular-shaped landform is formed. As it looks like the Greek letter delta, it is known as delta. The river bifurcates at the delta and flows along its sides.

WBBSE Class 7 Geography Chapter 4 Landforms Multiple Choice Questions 

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WBBSE Class 7 Geography Chapter 4 Landforms Multiple Choice Questions

Question 1. Landforms can be classified into types based on their altitude, geological structure, slope, ruggedness, etc.

  1. 3
  2. 4
  3. 5

Answer: 1. 3

Question 2. The average height of a mountain is-

  1. More than 900 metres
  2. Less than 1000 metres
  3. Less than 500 metres

Answer: 1. More than 900 metres

Read And Learn Also WBBSE Class 7 Geography Multiple Choice Questions 

Question 3. The Rocky Mountains are located in the continent of-

  1. North America
  2. Asia
  3. Europe

Answer: 1. North America

WBBSE Class 7 Geography Chapter 4 Landforms Multiple Choice Questions

Question 4. Himalayas are-

  1. Fold mountains
  2. Igneous mountains
  3. Block mountains

Answer: 1. Fold mountains

Question 5. Crumpled rock structures are seen in

  1. Fold mountains
  2. Block mountains
  3. Erosional mountains

Answer: 1. Fold mountains

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Question 6. The mountains, formed due to the folding of the underlying rock and resembling the shape of a wave, are called-

  1. Fold mountains
  2. Block mountains
  3. Igneous mountains

Answer: 1. Fold mountains

Question 7. The fold mountains are primarily made up of-

  1. Sedimentary rocks
  2. Igneous rocks
  3. Metamorphic rocks

Answer: 1. Sedimentary rocks

Question 8. Mountains that are formed due to the rupture or fault in the rock-beds are called-

  1. Fold mountains
  2. Block mountains
  3. Igneous mountains

Answer: 2. Block mountains

Question 9. Faults can be seen in-

  1. Fold mountains
  2. Block mountains
  3. Volcanic mountains

Answer: 2. Block mountains

Question 10. Horst is a type of-

  1. Block mountain
  2. Valley
  3. Ridge

Answer: 1. Block mountains

Question 11. A is generally seen beside a block mountain or horst.

  1. Fold mountain
  2. Plain
  3. Rift valley

Answer: 3. Rift Valley

Question 12. The river flows through a rift valley.

  1. Mahanadi
  2. Narmada
  3. Sabarmati

Answer: 2. Narmada

Question 13. The Satpura Range located in Central India is an example of a/an-

  1. Block mountain
  2. Igneous mountain
  3. Relict mountain

Answer: 1. Block mountain

Question 14. Nilgiri Hills are-

  1. Block mountains
  2. Rigneous mountains
  3. Relict mountains

Answer: 1. Block mountain

Question 15. mountains are formed due to the deposition of lava on the Earth’s surface.

  1. Volcanic
  2. Fold
  3. Block

Answer: 1. Volcanic

Question 16. Mt. Fujiyama in Japan is an example of a-

  1. Block mountain
  2. Volcanic mountain
  3. Fold mountain

Answer: 2. Volcanic mountain

Question 17. Mt. Vesuvius is an example of-

  1. An active volcano
  2. A dormant volcano
  3. An extinct volcano

Answer: 1. An active volcano

Question 18. Mt. Krakatoa of Indonesia is an example of-

  1. A fold mountain
  2. A block mountain
  3. An igneous mountain

Answer: 3. An igneous mountain

Question 19. Which of the following is a volcano in Italy?

  1. Mt. Vesuvius
  2. Mt. Fujiyama
  3. Barren Island

Answer: 1. Mt. Vesuvius

Question 20. Barren Island volcano is situated in-

  1. India
  2. Japan
  3. Italy

Answer: 1. India

Question 21. Relict mountains are also known as-

  1. Volcanic mountains
  2. Residual mountains
  3. Block mountains

Answer: 2. Residual mountains

Question 22. Which of the following is a famous hill in the Bankura district of West Bengal?

  1. Paresh Nath
  2. Ajodhya
  3. Susunia

Answer: 3. Susunia

Question 23. Prashanth is an example of a-

  1. Hill
  2. Plain
  3. Mountain

Answer: 1. Hill

Question 24. The highest part of a mountain is called-

  1. Peak
  2. Valley
  3. Ridge

Answer: 1. Peak

Question 25. Mt. Everest is a mountain-

  1. Peak
  2. Range
  3. Knot

Answer: 1. Peak

Question 26. An elongated lowland between two mountains is called a-

  1. Valley
  2. Peak
  3. Ridge

Answer: 1. Valley

Question 27. The place at which several mountain ranges meet is called a mountain-

  1. Peak
  2. Knot
  3. Range

Answer: 2. Knot

Question 28. An area of highland with a steep slope and flat terrain, resembling the shape of a table is called a-

  1. Plain
  2. Plateau
  3. Mountain

Answer: 2. Plateau

Question 29. A plateau is also referred to as a

  1. Tableland
  2. Hinterland
  3. Polderland

Answer: 1. Tableland

Question 30. Chhotanagpur Plateau is an example of a/an-

  1. Intermontane Plateau
  2. Lava Plateau
  3. Dissected Plateau

Answer: 3. Dissected Plateau

Question 31. The lava plateau in Maharashtra is also known as the-

  1. Malwa Plateau
  2. Bundelkhand Plateau
  3. Deccan Trap

Answer: 3. Deccan Trap

Question 32. The Tibetan Plateau is an example of a/an-

  1. Dissected Plateau
  2. Lava Plateau
  3. Intermontane Plateau

Answer: 3. Intermontane Plateau

Question 33. Which plateau is also known as the ‘Roof of the World’?

  1. Ladakh Plateau
  2. Tibetan Plateau
  3. Pamir Plateau

Answer: 3. Pamir Plateau

Question  34. The largest plateau in the world is the-

  1. Pamir Plateau
  2. Tibetan Plateau
  3. Arabian Plateau

Answer: 2. Tibetan Plateau

Question 35. The height of the Pamir Plateau is-

  1. 4873 m
  2. 8848 m
  3. 2000 m

Answer: 1. 4873 m

Question 36. Which of the following is a plateau of northern India?

  1. Chhotanagpur Plateau
  2. Ladakh Plateau
  3. Malwa Plateau

Answer: 2. Ladakh Plateau

Question 38. Most of the land areas on the Earth are-

  1. Plains
  2. Plateaus
  3. Mountains

Answer: 1. Plains

Question 39. The average altitude of a plain from the sea level is-

  1. Less than 300 metres
  2. More than 300 metres
  3. More than 600 metres

Answer: 1. Less than 300 metres

Question 40. The Northern Plains of India are an example of-

  1. Alluvial Plains
  2. Coastal Plains
  3. Glacial Plains

Answer: 1. Alluvial Plains

Question 41. An example of a lava plain is-

  1. Deccan Trap
  2. Indo-Gangetic Plain
  3. Brahmaputra Plain

Answer: 1. Deccan Trap

Question 42. _______ are formed due to the deposition of sand carried by wind to distant places.

  1. Alluvial plains
  2. Loess plains
  3. Coastal plains

Answer: 2. Loess plains

Question 43. Which of the following is formed by the deposition of sand particles?

  1. Alluvial plain
  2. Loess plain
  3. Lava plain

Answer: 2. Loess plain

Question 44. The world’s largest deltaic plain has been formed at the mouth of the river-

  1. Ganges
  2. Nile
  3. Tigris

Answer: 1. Ganges

Question 45. Maximum population density is observed in the-

  1. Plains
  2. Plateaus
  3. Mountains

Answer: 1. Plains

Question 46. Sustenance of life is much easier in the-

  1. Plains
  2. Mountains
  3. Plateaus

Answer: 1. plains

Question 47. Most ancient civilisations have thrived on-

  1. Alluvial Plains
  2. Lava Plains
  3. Loess Plains

Answer: 1. Alluvial Plains

WBBSE Class 7 Geography Chapter 4 Landforms Notes

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WBBSE Class 7 Geography Chapter 4 Landforms Introduction

Not all parts of the Earth’s surface are the same. Some places are high, some places are undulating and some places are low-lying plains. This diversity of land on the Earth’s surface is called landform. The asthenosphere is the viscous or semi-liquid layer that has a depth of about 700 km below the Earth’s crust. The crust is divided into several pieces which are floating and moving within the asthenosphere. These pieces are called plates.

All landforms have been created by two main types of forces. Forces that act from within the Earth’s surface are called endogenetic forces and the ones acting from outside the Earth’s surface are called exogenetic forces. A mountain is a landform formed by rocks, usually more than 900 metres high and extends over a wide area. When the land gets uplifted due to compressional forces acting on it, a fold mountain is formed.

Read And Learn Also WBBSE Class 7 Geography Notes

Tectonic movements may sometimes lead to the formation of cracks along the Earth’s surface. The middle segment of these cracks may either uplift or the segments of both sides may subduce so that the middle segment forms a block mountain. Lava, ashes and pieces of rocks that gush out during a volcanic eruption get accumulated all around a volcano, thereby forming a conical highland called a volcanic mountain. The topmost part of a mountain which has a needle-like shape is called a mountain peak.

WBBSE Class 7 Geography Chapter 4 Landforms Notes

The lowland or depression between two mountains or mountain ranges is called a valley. A series of mountains, or more or less parallel lines of mountains extending over a large area is collectively called a mountain range.

A high elevated place on the Earth’s surface, where several mountain ranges meet or, from where several mountain ranges radiate in different directions, is known as a knot. A landform that suddenly rises over its surroundings with steep slopes on all sides, generally over 300m is called a plateau. It is also called a tableland.

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Intermontane Plateaus are the highest and the most expansive type of plateaus. Vast stretches in South Africa, Western Australia, Antarctica and Greenland are occupied by Continental Plateaus.

Lava gushing during volcanic eruptions and spreading like sheets through large stretches of land can form expansive lava plateaus or Volcanic Plateaus. Plateaus are dissected by intervening rivers with the dissected pieces standing apart, interspersed by river valleys are called Dissected Plateaus.

A plain is a low, flat stretch of land. Lava plains form when lava accumulates over vast, flat, low-lying stretches. Deposits of alluvium accumulating in the valleys and beds of rivers, seas and lakes for many years form alluvial plains. A flat plain formed by the deposition of wind-blown fine sand particles is known as a loess plain.

WBBSE Class 7 Geography Chapter 3 Air Pressure Multiple Choice Questions

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WBBSE Class 7 Geography Chapter 3 Air Pressure Multiple Choice Questions

Question 1. The blanket of air surrounding the Earth is called-

  1. Atmosphere
  2. Hydrosphere
  3. Lithosphere

Answer: 1. Atmosphere

Question 2. The force exerted by the air per unit area on the Earth’s surface is called atmospheric-

  1. Pressure
  2. Humidity
  3. Density

Answer: 1. Pressure

Read And Learn Also WBBSE Class 7 Geography Multiple Choice Questions 

Question 3. Normal atmospheric pressure at sea level is approximate-

  1. 1000 MB
  2. 1020.5 MB
  3. 1013.25 MB

Answer: 3. 1013.25 MB

WBBSE Class 7 Geography Chapter 3 Air Pressure Multiple Choice Questions

Question 4. Air exerts pressure on the Earth’s surface due to the-

  1. Transparency of air
  2. Gravitational attraction of the earth
  3. Gaseous nature of air

Answer: 2. Gravitational attraction of the earth

Question 5. Atmospheric pressure falls by for every 110 metres of ascent.

  1. 1 cm of mercury
  2. 1 mm of mercury
  3. 1 MB.

Answer: 1. 1 cm of mercury

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Question 6. The average air pressure is-

  1. 1 kg per square centimetre
  2. 1 tonne per square centimetre
  3. 1 gram per square centimetre

Answer: 1. 1 kg per square centimetre

Question 7. Normal atmospheric pressure over the Earth varies between-

  1. 980 mb to 1050 mb
  2. 580 mb to 650 mb
  3. 180 mb to 270 mb

Answer: 1. 980 Mb to 1050 Mb

Question 8. Atmospheric pressure is measured by an instrument called-

  1. Thermometer
  2. Barometer
  3. Hygrometer

Answer: 2. Barometer

Question 9. The barometer was invented by-

  1. Torricelli
  2. Galileo
  3. Newton

Answer: 1. Torricelli

Question 10. Is used in barometers.

  1. Oil
  2. Water
  3. Mercury

Answer: 3. Mercury

Question 11. Gradual fall in the mercury column in a barometer indicates the probable occurrence of-

  1. Rain
  2. Clear weather
  3. Blue sky

Answer: 1. Rain

Question 12. The principal cause of variation in the atmospheric pressure is-

  1. Air flow
  2. Temperature
  3. Latitude

Answer: 2. Temperature

Question 13. We do not feel the atmospheric pressure, because-

  1. It is balanced by the fluid pressure inside our body
  2. It is less
  3. Our body can tolerate the pressure

Answer: 1. It is balanced by the fluid pressure inside our body

Question 14. Atmospheric pressure on a high mountain range is-

  1. More than that at sea level
  2. Less than that at sea level
  3. Same as that at sea level

Answer: 2. Less than that at sea level

Question 15. At the top of Mount Everest, the atmospheric pressure is-

  1. 330 millibar
  2. 30 millibar
  3. 1000 millibar

Answer: 1. 330 millibar

Question 16. With an increase in altitude the atmospheric pressure-

  1. Increases
  2. Remains the same
  3. Decreases

Answer: 3. Decreases

Question 17. In hilly regions the boiling point of liquids-

  1. Increases
  2. Remains the same
  3. Decreases

Answer: 3. Decreases

Question 18. With an increase in atmospheric pressure, the boiling point of liquids-

  1. Increases
  2. Decreases
  3. Remains The Same

Answer: 1. Increases

Question 19. Water vapour is than air.

  1. Lighter
  2. Heavier
  3. At times lighter or heavier

Answer: 1. Lighter

Question 20. The amount of water vapour present in the air is-

  1. Variable
  2. Same
  3. Increases

Answer: 1. Variable

Question 21. In the monsoon season, atmospheric pressure remains-

  1. High
  2. Low
  3. Very high

Answer: 2. Low

Question 22. The pressure of saturated air is-

  1. Low
  2. High
  3. Moderate

Answer: 1. Low

Question 23. With an increase in pressure, the volume of air-

  1. Increases
  2. Remains The Same
  3. Decreases

Answer: 3. Decreases

Question 24. When air is heated up, the molecules contained within it move-

  1. Faster
  2. At the same speed
  3. Slower

Answer: 1. Faster

Question 25. When hot air cools down, its density-

  1. Increases
  2. Remains the same
  3. Decreases

Answer: 1. Increases

Question 26. Permanent low-pressure belts prevail over the-

  1. Equatorial Region
  2. Subtropical Region
  3. Polar Region

Answer: 1. Equatorial Region

Question 27. The number of permanent pressure belts on the Earth’s surface are-

  1. 5
  2. 6
  3. 7

Answer: 3. 7

Question 28. The sub-polar low-pressure belt near the Antarctic Circle is observed around the-

  1. 66½° north latitude
  2. 66½° south latitude
  3. 23½° south latitude

Answer: 2. 66½° south latitude

Question 29. Lies between 60°-90° N and S Latitudes.

  1. High-pressure belt
  2. Calm pressure belt
  3. Low-pressure belt

Answer: 3. Low-pressure belt

Question 30. Forms due to extreme cold conditions in both polar regions.

  1. High-pressure belt
  2. Low-pressure belt
  3. Calm belt

Answer: 1. High-pressure belt

Question 31. In the equatorial region, the atmospheric pressure is-

  1. High
  2. Low
  3. Moderate

Answer: 2. Low

Question 32. The pressure zone prevails over the North Pole is-

  1. High
  2. Low
  3. Moderate

Answer: 1. High

Question 33. Low-pressure belt lies between-

  1. 5°N-5°S latitude
  2. 20°-30°N and S latitude
  3. 30°-40°N and S latitude

Answer: 1. 5°N-5°S latitude

Question 34. Sub-tropical high-pressure belts exist between-

  1. 25°-35°N and S latitudes
  2. 5°-10°N and S latitudes
  3. 30°-60°N and S latitudes

Answer: 1. 25°-35°N and S latitudes

Question 35. Polar high-pressure belts form between-

  1. 90°N and S latitudes
  2. 25°-35°N and S latitudes
  3. 30°-60°N and S latitudes

Answer: 1. 90°N and S latitudes

Question 36. The number of pressure cells observed in the northern hemisphere is that in the southern hemisphere.

  1. More than
  2. Same as
  3. Less than

Answer: 1. More than

Question 37. The size of pressure cells is elongated in the-

  1. Southern hemisphere
  2. Eastern hemisphere
  3. Northern hemisphere

Answer: 1. Southern hemisphere

Question 38. The line joining places of equal pressure on the Earth’s surface is called-

  1. Contour
  2. Isotherm
  3. Isobar

Answer: 3. Isobar

Question 39. The isobars stretch along-

  1. East-west direction
  2. North-south direction
  3. North-west direction

Answer: 1. East-west direction

Question 40. Closely-spaced isobars indicate the presence of-

  1. High-Velocity Winds
  2. Low-Velocity Winds
  3. Feeble Winds

Answer: 1. High-Velocity Winds

Question 41. Winds blowing from high-pressure zones

  1. Cold in nature
  2. Hot in nature
  3. Light in nature

Answer: 1. Cold in nature

Question 42. The tropical cyclones which form over the China Sea are called-

  1. Typhoon
  2. Tornado
  3. Willy Willy

Answer: 1. Typhoon

Question 43. The tropical cyclones which form over north-west Australia are called-

  1. Willy Willy
  2. Tornado
  3. Hurricane

Answer: 1. Willy Willy

Question 44. The whirlwinds that form on the Indian Ocean are known as-

  1. Cyclones
  2. Hurricanes
  3. Typhoons

Answer: 1. Cyclones

Question 45. The average air temperature at the top of Mount Everest is-

  1. -20°C to -35°C
  2. -200°C to -350°C
  3. 20°C to 35°C

Answer: 1. -20°C to -35°C

Question 46. In Puri, the atmospheric pressure is approximate-

  1. 1000 millibar
  2. 330 millibar
  3. 30 millibar

Answer: 1. 1000 millibar

Question 47. The speed of air is measured in units of-

  1. Millibar
  2. Kilogram
  3. Knot

Answer: 3. Knot

WBBSE Class 7 Geography Chapter 3 Air Pressure Notes

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WBBSE Class 7 Geography Chapter 3 Air Pressure Introduction

Air is a mixed gaseous substance. Like other substances, the air has its own mass. The weight of air is felt on the surface of the Earth due to gravity. For this weight, the value of the force exerted by the air per unit area on the surface is called the air pressure. There are mainly two types of air pressure high pressure and 2 low pressure. The pressure exerted at sea level by 76 cm of mercury column at 45° north latitude, is called the standard or average atmospheric pressure. It is equal to 1 kg per sq cm or 1013.25 Mb.

Read And Learn Also WBBSE Class 7 Geography Notes

The unit that is used to measure air pressure is a millibar. 1 millibar is the pressure exerted by 0.02953 inches. column of mercury. In some definite regions on the Earth’s surface, high pressure or low pressure is observed throughout the year. These definite regions of atmospheric pressure surround the Earth in the form of belts. These are called atmospheric pressure belts.

WBBSE Class 7 Geography Chapter 3 Air Pressure Notes

An imaginary line joining all the places on the Earth’s surface having equal atmospheric pressure is known as an isobar. It is shown in the weather map expressing its value in millibars. If the average air pressure is more than 1013.25 MB, it is known as high pressure.

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The region where the atmospheric pressure is higher than the surrounding areas is known as the high-pressure area. It is denoted on the map as ‘H’. If the average air pressure is less than 986 MB, it is known as low pressure.

The region where the atmospheric pressure is lower than the surrounding areas is known as the low-pressure area. It is denoted on the map as ‘L’ The horizontal movement of air along the surface of the Earth from a high-pressure area to a low-pressure area is known as the wind.