World Geography Quiz - 2, General Knowledge - Current Affairs MCQ

http://en.wikipedia.org/wiki/List_of_countries_by_gold_production

The Hydrological Cycle
The hydrological cycle, also known as the water cycle, is a conceptual model that describes the movement and storage of water on Earth. It involves various processes, such as evaporation, condensation, precipitation, and runoff. This cycle is vital for the distribution of water resources and the maintenance of life on our planet.
Key Points:
- The hydrological cycle involves the continuous movement of water between different components of the Earth's system.
- The components of the hydrological cycle include the biosphere (living organisms), hydrosphere (water bodies), atmosphere (air), and lithosphere (land).
- The cycle begins with the evaporation of water from the Earth's surface, primarily from oceans, lakes, and rivers.
- The water vapor rises into the atmosphere and undergoes condensation, forming clouds.
- Clouds then release moisture in the form of precipitation, which can be in the form of rain, snow, sleet, or hail.
- Precipitation can either infiltrate into the ground, becoming groundwater, or flow over the land as runoff.
- Some water returns to the atmosphere through evaporation and transpiration (release of water vapor by plants).
- The remaining water in the ground eventually reaches rivers, lakes, and oceans, completing the cycle.
Summary:
In summary, the hydrological cycle is a conceptual model that describes the continuous movement and storage of water on Earth. It involves processes such as evaporation, condensation, precipitation, and runoff, and it plays a crucial role in the distribution of water resources and the sustenance of life on our planet.

Basalt plateau:
- Basalt plateau is the least explosive type of volcano.
- It is characterized by extensive lava flows and a low viscosity lava that easily spreads out.
- The lava is composed mainly of basaltic magma, which is less volatile and has a lower gas content compared to other types of magma.
- Basaltic magma has a lower silica content, which makes it less viscous and allows it to flow more easily.
- The eruptions of basalt plateau volcanoes are generally non-explosive and are characterized by effusive lava flows rather than explosive ash and pyroclastic eruptions.
- The lava flows from basalt plateau volcanoes can cover large areas and form flat, broad plateaus or gently sloping shield-shaped volcanoes.
- Examples of basalt plateau volcanoes include the Deccan Traps in India and the Columbia River Basalt Group in the United States.
Cinder cone:
- Cinder cones are small, steep-sided volcanoes that are formed by explosive eruptions.
- They are composed of loose pyroclastic material, such as cinders, ash, and volcanic bombs.
- Cinder cone eruptions are generally short-lived and are characterized by violent explosions that eject volcanic material into the air.
- The eruptions of cinder cone volcanoes are often accompanied by loud explosions and the formation of a crater at the summit.
- Examples of cinder cone volcanoes include Parícutin in Mexico and Sunset Crater in the United States.
Shield volcanoes:
- Shield volcanoes are large, broad volcanoes with gentle slopes that are formed by the eruption of fluid basaltic lava.
- They are characterized by a shield-like shape, with a low profile and a broad summit.
- The eruptions of shield volcanoes are generally non-explosive and are characterized by the effusion of fluid lava flows.
- The lava flows from shield volcanoes can cover large areas and form extensive lava fields.
- Examples of shield volcanoes include Mauna Loa and Kilauea in Hawaii and Mauna Kea in the United States.
Composite volcanoes:
- Composite volcanoes, also known as stratovolcanoes, are tall, steep-sided volcanoes that are composed of alternating layers of lava flows, pyroclastic material, and volcanic ash.
- They are formed by both explosive and effusive eruptions.
- The eruptions of composite volcanoes can be highly explosive and are often characterized by the eruption of ash, pumice, and volcanic bombs.
- Composite volcanoes have a conical shape, with a steep summit and a narrow base.
- Examples of composite volcanoes include Mount St. Helens in the United States and Mount Fuji in Japan.
Summary:
- The least explosive type of volcano is the basalt plateau, which is characterized by non-explosive lava flows and a low viscosity basaltic magma.
- Cinder cones, shield volcanoes, and composite volcanoes are more explosive and are formed by different types of eruptions and magma compositions.

Answer:
The largest fish exporting region in the world is the north-east atlantic region. Here is a detailed explanation:
1. Introduction:
The fish exporting industry plays a significant role in global trade, with various regions around the world being major contributors. Among these regions, the north-east atlantic region stands out as the largest exporter of fish.
2. North-East Atlantic Region:
The north-east atlantic region encompasses countries such as Norway, Iceland, and Denmark. These countries have extensive coastlines and rich fishing grounds, making them ideal for fishery activities. They have established fishing fleets and well-developed infrastructure for processing and exporting fish.
3. Factors contributing to its dominance:
Several factors contribute to the north-east atlantic region's status as the largest fish exporter:
- Abundance of fish stocks: The north-east atlantic region benefits from the presence of abundant fish stocks, including species like cod, herring, and mackerel. This allows for a consistent supply of fish for export.
- Sustainable fishing practices: The countries in the north-east atlantic region have implemented strict regulations and sustainable fishing practices to ensure the long-term viability of their fish stocks. This commitment to sustainability enhances their reputation as reliable exporters.
- Advanced processing facilities: The region boasts advanced processing facilities that enable efficient handling, packaging, and preservation of fish products. This ensures the quality and freshness of the exported fish.
- Established trade networks: Over the years, the north-east atlantic region has developed robust trade networks, including partnerships with importers and distributors worldwide. This connectivity facilitates the export of fish to various markets.
4. Other regions:
While the north-east atlantic region is the largest fish exporter, other regions also contribute significantly to the global fish trade:
- The north-east pacific region, including countries like the United States, Canada, and Chile, is known for its salmon and tuna exports.
- The north-west pacific region, which includes countries like China, Japan, and South Korea, is a major exporter of various fish species, including shrimp, crab, and squid.
- The south-east Asian region, comprising countries like Thailand, Vietnam, and Indonesia, is renowned for its aquaculture industry and exports a wide range of fish and seafood products.
Conclusion:
In conclusion, the north-east atlantic region is the largest fish exporting region in the world. Its abundant fish stocks, sustainable fishing practices, advanced processing facilities, and established trade networks contribute to its dominance in the global fish trade. However, it is important to note that other regions also play significant roles in fish exports, highlighting the diverse nature of the global fishery industry.

Answer:

The largest country in the world by geographical area is Russia.

Below are the details explaining why Russia is the largest country:

• Geographical Area: Russia covers a vast area of 17.1 million square kilometers.


• Size Comparison: It is approximately twice the size of the second-largest country, Canada.


• Continental Span: Russia spans across both Eastern Europe and Northern Asia.


• Bordering Countries: Russia shares its borders with 14 countries, including China, Mongolia, Kazakhstan, Norway, and Finland.


• Population: Despite its massive size, Russia has a relatively low population density due to the vast amount of uninhabited land.


• Topography: Russia has diverse topography, including vast plains, mountain ranges like the Ural Mountains, and numerous rivers and lakes.


• Administrative Divisions: Russia is divided into 85 federal subjects, including 22 republics, 9 krais, 46 oblasts, 3 federal cities, and 1 autonomous oblast.


• Natural Resources: It is rich in various natural resources, including oil, gas, minerals, and timber.


• Climate: Russia experiences a wide range of climates, from arctic in the north to subtropical in the south.

Therefore, considering its immense size, diverse geography, and extensive borders, Russia is rightfully considered the largest country in the world by geographical area.

Explanation:
To find the answer to this question, we need to understand the concept of hot and cold deserts and their land area in the world.
Hot and Cold Deserts:
- Hot deserts are characterized by high temperatures and low precipitation. Examples include the Sahara Desert in Africa and the Arabian Desert in the Middle East.
- Cold deserts are characterized by low temperatures and sparse vegetation. Examples include the Gobi Desert in Asia and the Patagonian Desert in South America.
Land Area of the World:
- The total land area of the world is approximately 148.94 million square kilometers.
Calculating the Land Area occupied by Hot and Cold Deserts:
- The exact land area occupied by hot and cold deserts may vary, but it is estimated to be around 33% of the total land area.
- Therefore, the hot and cold deserts together occupy nearly 1/3rd (or 33%) of the land area of the world.
Answer:
Therefore, the correct answer is option C: 1/3rd.

Explanation:
The highest average salinity amongst the following seas is reported from the Dead Sea. Here's a detailed explanation:
Salinity:
- Salinity refers to the concentration of dissolved salts in water.
- It is typically measured in parts per thousand (ppt) or as a percentage.
Comparison of Average Salinity:
- To determine the sea with the highest average salinity among the given options, we need to compare the salinity levels of each sea.
- The average salinity of the Dead Sea is approximately 34.2%, making it the saltiest sea in the world.
- The Red Sea has an average salinity of around 40 ppt.
- The Black Sea has an average salinity of about 17 ppt.
- The Mediterranean Sea has an average salinity of approximately 39 ppt.
Conclusion:
- Among the given options, the Dead Sea has the highest average salinity.
- Therefore, the correct answer is option A: Dead Sea.

The Himalayan mountain system belongs to the category of Fold mountains.
Fold mountains:
- Fold mountains are formed by the folding of rock layers due to tectonic forces.
- They are characterized by long, linear ridges and valleys.
- The Himalayas, along with the Alps, Andes, and Rockies, are some of the most well-known examples of fold mountains.
- These mountains are formed when two tectonic plates collide, causing the crust to buckle and fold.
- The Himalayas were formed as a result of the collision between the Indian and Eurasian plates.
- The Indian plate, moving at a rate of about 5 centimeters per year, is still pushing against the Eurasian plate, causing the Himalayas to rise.
- The Himalayan mountain range stretches across several countries, including India, Nepal, Bhutan, China, and Pakistan.
- It is home to some of the highest peaks in the world, including Mount Everest, which is the highest peak on Earth.
Other mountain types:
- Volcanic mountains: These mountains are formed by volcanic activity and are characterized by volcanic cones and craters. Examples include Mount Vesuvius and Mount Fuji.
- Residual mountains: These mountains are formed by the erosion of older mountain ranges. They are typically lower in elevation and have rounded peaks. The Appalachian Mountains in the United States are an example of residual mountains.
- Block mountains: These mountains are formed when large blocks of the Earth's crust are uplifted and tilted. The Sierra Nevada in the United States is an example of block mountains.
In summary, the Himalayan mountain system belongs to the category of fold mountains, which are formed by the folding of rock layers due to tectonic forces.

The heavy day soils that show significant expansion and contraction due to the presence or absence of moisture is called Vertisols.
Explanation:
Vertisols are a type of soil that exhibit significant expansion and contraction due to changes in moisture content. These soils are characterized by a high clay content, particularly smectite clay minerals, which have the ability to swell and shrink with changes in moisture levels.
Here is a detailed explanation of why Vertisols are the correct answer:
- Definition: Vertisols are a soil order in the USDA soil taxonomy. They are characterized by a high clay content and exhibit significant swelling and shrinking behavior with changes in moisture content.
- Clay Content: Vertisols typically have a clay content of 30% or more. The clay particles in these soils have a unique mineralogy, mainly dominated by smectite clay minerals. Smectite clays have the ability to adsorb water molecules and expand, leading to the swelling behavior of Vertisols.
- Swelling Behavior: When Vertisols are exposed to water, the clay particles absorb the water molecules and expand. This expansion can cause significant changes in the soil volume, leading to the formation of cracks and fissures when the soil dries out. This is known as the cracking behavior of Vertisols.
- Contrasting Behavior: The swelling and shrinking behavior of Vertisols is quite unique compared to other soil types. While most soils shrink when they dry out, Vertisols can undergo significant shrinkage upon drying, leading to the formation of deep cracks and crevices.
- Moisture Influence: The expansion and contraction of Vertisols are strongly influenced by moisture content. These soils experience the most significant changes in volume when transitioning between wet and dry conditions.
Therefore, the correct answer is B: Vertisols.

The HBJ Upgradation project increased the capacity of the HBJ pipeline from 18.2 MM SC MD to 33.4 MM SC MD.
Here is a detailed explanation of the solution:
Background:
The HBJ pipeline is a major gas pipeline system that transports natural gas from the Hazira-Bijaipur-Jagdishpur region in India. The pipeline plays a crucial role in supplying gas to various industries and consumers in the region.
Objective:
The objective of the HBJ Upgradation project was to increase the capacity of the pipeline to meet the growing demand for natural gas in the region.
Upgrade details:
The upgrade project successfully increased the capacity of the HBJ pipeline from its previous capacity of 18.2 MM SC MD to a new capacity of 33.4 MM SC MD.
Impact:
The upgrade has significant implications for the region, as it allows for a higher volume of natural gas to be transported through the pipeline. This increased capacity enables the pipeline to meet the growing demand for natural gas and support the development of industries and households in the region.
Conclusion:
The HBJ Upgradation project successfully increased the capacity of the HBJ pipeline from 18.2 MM SC MD to 33.4 MM SC MD. This upgrade has positive implications for the region, as it allows for a higher volume of natural gas to be transported and supports the growth and development of various industries and consumers.

The highest mountains on earth, namely Mount Everest, K2, and Kanchenjanga, are located in the greater Himalayas.
Explanation:
The Himalayas, a mountain range in Asia, is home to some of the tallest peaks in the world. Mount Everest, standing at an impressive height of 8,848 meters, is the highest mountain on earth. K2, also known as Mount Godwin-Austen, is the second-highest peak, with a height of 8,611 meters. Kanchenjanga, located on the border between Nepal and India, is the third-highest mountain, reaching a height of 8,586 meters.
The Himalayas can be divided into three main regions based on their altitude and geological features: the greater Himalayas, the lesser Himalayas, and the outer Himalayas.
The greater Himalayas:
- Also known as the Himadri or Inner Himalayas, this region is the highest and most prominent section of the Himalayan mountain range.
- It includes the highest peaks, such as Mount Everest, K2, and Kanchenjanga.
- The greater Himalayas are characterized by snow-covered peaks, glaciers, and deep valleys.
- This region is primarily composed of granites, gneisses, and other metamorphic rocks.
The lesser Himalayas:
- Also known as the Himachal or Middle Himalayas, this region lies to the south of the greater Himalayas.
- It consists of lower peaks and ranges, with an average height of around 3,700 meters.
- The lesser Himalayas are characterized by forests, meadows, and terraced fields.
- This region is primarily composed of sedimentary rocks, including sandstone, limestone, and shale.
The outer Himalayas:
- Also known as the Siwalik or Sub-Himalayas, this region lies to the south of the lesser Himalayas.
- It consists of foothills, valleys, and plains.
- The outer Himalayas are characterized by alluvial deposits, river systems, and thick forests.
- This region is primarily composed of unconsolidated sediments, including sand, gravel, and clay.
Therefore, based on the location of the highest mountains on earth, Mount Everest, K2, and Kanchenjanga, it can be concluded that they are situated in the greater Himalayas.

Key Points:

• Infrared radiation from the sun is strongly absorbed by certain atmospheric gases.


• The main gases responsible for absorbing infrared radiation are carbon dioxide (CO2) and water vapour (H2O).


• Ozone (O3) also absorbs some infrared radiation, but to a lesser extent compared to CO2 and H2O.


• Out of the given options, carbon dioxide is the correct answer because it is the primary gas responsible for absorbing infrared radiation.

Explanation:

Infrared radiation is a form of electromagnetic radiation emitted by the sun. When this radiation interacts with the Earth's atmosphere, certain gases in the atmosphere can absorb and trap the heat energy carried by the infrared radiation. This process is known as the greenhouse effect and is responsible for keeping the Earth's surface warm enough to support life.

Out of the gases present in the Earth's atmosphere, carbon dioxide and water vapour are the most significant in terms of their ability to absorb infrared radiation. Here's why:

Carbon Dioxide (CO2):

• CO2 is a greenhouse gas that is naturally present in the Earth's atmosphere.


• It has the ability to absorb and re-emit infrared radiation in the atmosphere.


• This absorption process traps some of the heat energy, preventing it from escaping back into space.


• The increasing concentration of CO2 in the atmosphere due to human activities, such as the burning of fossil fuels, has led to an enhanced greenhouse effect and global warming.

Water Vapour (H2O):

• Water vapour is another important greenhouse gas that can absorb and re-emit infrared radiation.


• It is present in varying amounts in the Earth's atmosphere, depending on factors such as temperature and humidity.


• Water vapour acts as a positive feedback mechanism in the climate system. As the atmosphere warms due to the greenhouse effect, more water evaporates, leading to increased water vapour content in the atmosphere.


• This, in turn, amplifies the greenhouse effect and contributes to further warming.

Ozone (O3):

• Ozone is a gas that is primarily found in the Earth's stratosphere, where it forms the ozone layer.


• While ozone can absorb some infrared radiation, its role in the greenhouse effect is relatively minor compared to CO2 and H2O.


• The main function of the ozone layer is to absorb and block harmful ultraviolet (UV) radiation from the sun.

Given the options provided, carbon dioxide (option A) is the correct answer because it is the primary gas responsible for absorbing infrared radiation. Water vapour (option B) is also a significant absorber of infrared radiation, but carbon dioxide is more widely recognized as a greenhouse gas. Option C, which combines carbon dioxide and water vapour, is also correct since both gases contribute to the absorption of infrared

The latitude of a place expresses its angular position relative to the plane of:


A: axis of earth
- The axis of the earth refers to the imaginary line around which the earth rotates.
- The latitude of a place does not express its angular position relative to the axis of the earth.
- Therefore, the answer is not A.
B: north pole
- The north pole is the northernmost point on the earth's surface.
- The latitude of a place does not express its angular position relative to the north pole.
- Therefore, the answer is not B.
C: south pole
- The south pole is the southernmost point on the earth's surface.
- The latitude of a place does not express its angular position relative to the south pole.
- Therefore, the answer is not C.
D: equator
- The equator is an imaginary line that divides the earth into the Northern Hemisphere and the Southern Hemisphere.
- The latitude of a place expresses its angular position relative to the equator.
- The equator has a latitude of 0 degrees, and latitudes increase as you move towards the poles.
- Therefore, the correct answer is D: equator.
Overall, the latitude of a place expresses its angular position relative to the equator, not the axis of the earth, the north pole, or the south pole.

The correct answer is A: polygenetic landforms. Polygenetic landforms are influenced by multiple processes, including weathering, erosion, and deposition. Here is a detailed explanation:
1. Polygenetic landforms: These are landforms that are shaped and influenced by several processes over a long period of time, typically thousands or millions of years.
2. Weathering: This process involves the breaking down of rocks and minerals on the Earth's surface. Weathering can be caused by physical, chemical, or biological factors. Over time, weathering can shape and modify the landforms.
3. Erosion: Erosion refers to the movement of weathered materials, such as soil, rock fragments, and sediments, from one place to another. It is typically caused by natural agents like water, wind, ice, or gravity. Erosion can wear down and reshape the landforms.
4. Deposition: Deposition occurs when eroded materials are deposited or laid down in a different location. This can happen when the transporting agent loses energy and can no longer carry the sediment. Deposition can contribute to the formation of new landforms or modify existing ones.
5. Multiple processes: Polygenetic landforms are the result of the combined effects of weathering, erosion, and deposition. These processes work together over a long period of time to shape and modify the landforms into their current state.
In conclusion, polygenetic landforms are influenced by the processes of weathering, erosion, and deposition. These landforms are the result of multiple processes acting over a long period of time and can exhibit a variety of shapes and features.

Explanation:
The initial increase of magnetic field in magnetic storms is caused by the compression of the magnetosphere due to the shock wave associated with the gusty solar wind. Here is a detailed explanation:
- Shock Wave: When the gusty solar wind reaches the Earth, it creates a shock wave due to the interaction between the solar wind and the Earth's magnetosphere.
- Compression of the Magnetosphere: The shock wave compresses the magnetosphere, which is the region surrounding the Earth where the magnetic field dominates the behavior of charged particles.
- Increased Magnetic Field: The compression of the magnetosphere leads to an increase in the strength of the magnetic field.
- This initial increase in the magnetic field is one of the characteristics of magnetic storms.
- Apart from the initial increase, magnetic storms also involve other phenomena such as the energization and acceleration of charged particles, which can cause disturbances in Earth's ionosphere and disrupt communication and navigation systems.
In summary:
- The initial increase of the magnetic field in magnetic storms is caused by the compression of the magnetosphere due to the shock wave associated with the gusty solar wind.

Answer:

The island state of Australia is Tasmania.

Here is a detailed solution:

• Australia: Australia is a country located in the southern hemisphere and is the world's sixth-largest country by total area.


• Island State: An island state is a political jurisdiction that consists of one or more islands. In the context of Australia, there is one island state.


• Tasmania: Tasmania is the island state of Australia. It is located about 240 km to the south of the Australian mainland and is separated by the Bass Strait.


• Geography: Tasmania is known for its diverse landscapes, including mountains, rainforests, and beautiful coastlines.


• Capital: The capital city of Tasmania is Hobart, which is also the largest city on the island.


• Population: Tasmania has a population of approximately 540,000 people as of 2021.


• Wildlife: Tasmania is home to unique wildlife, including the Tasmanian devil, which is a marsupial found only on the island.


• Tourism: Tasmania is a popular tourist destination, known for its natural beauty, national parks, and outdoor activities such as hiking, camping, and wildlife spotting.

In conclusion, the island state of Australia is Tasmania.

The Ice Age ended about 14,000 years ago.
Explanation:
- The Ice Age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets.
- It is believed that the most recent Ice Age, known as the Pleistocene Ice Age, began about 2.6 million years ago.
- The Pleistocene Ice Age consisted of multiple glacial and interglacial periods, with the last glacial period occurring approximately 110,000 to 12,000 years ago.
- The end of the last glacial period marked the end of the Ice Age.
- Geological evidence, such as the retreat of glaciers and the rise in sea levels, indicates that the Ice Age ended around 14,000 years ago.
- This is supported by various dating methods, including radiocarbon dating and analysis of ice cores.
- The end of the Ice Age led to significant changes in climate, vegetation, and animal populations, paving the way for the development of human civilizations.

Languages used in China:

• Chinese: Chinese is the official language of China and is spoken by the majority of the population.


• English: English is widely taught and spoken in China, especially in major cities and among younger generations.

Explanation:
China is a linguistically diverse country with several languages and dialects spoken across its vast territory. However, the most commonly used languages in China are Chinese and English. Here's a detailed explanation of the languages used in China:
Chinese:
- Chinese, specifically Mandarin, is the official language of China. It is the most widely spoken language in the country, with over 1 billion native speakers.
- Mandarin Chinese is based on the Beijing dialect and is the standard language used for communication in government, media, education, and business.
- Other Chinese dialects, such as Cantonese, Shanghainese, and Hokkien, are also spoken in China, particularly in specific regions.
English:
- English is taught as a compulsory subject in schools across China, starting from a young age. It is considered an important language for international communication and business.
- English proficiency is particularly high among younger generations and urban populations in China.
- English is widely used in international trade, tourism, technology, and education sectors.
It's worth noting that while Chinese and English are the primary languages used in China, there are also communities of speakers of other languages, such as Arabic, French, and Korean, particularly in expatriate communities and specific regions. However, these languages are not as widely spoken as Chinese and English.

Transport within the transporting medium can occur by suspension, solution, and traction. Let's break down each of these transport mechanisms in detail:
Suspension:
- Suspension is a form of transport where solid particles are carried within a fluid medium.
- The solid particles are often larger and denser than the fluid medium, causing them to be suspended and carried along by the flow of the fluid.
- Examples of suspension transport include sediment being carried by a river or dust particles being carried by wind.

- Solution transport occurs when dissolved substances are carried within a fluid medium.
- The dissolved substances are evenly distributed throughout the fluid, creating a homogeneous mixture.
- Examples of solution transport include the transport of nutrients in the bloodstream or the transport of dissolved minerals in groundwater.
Traction:
- Traction transport involves the movement of larger particles by rolling or sliding along the bottom of the transporting medium.
- This form of transport typically occurs in situations where the particles are too large to be suspended or dissolved in the fluid.
- Examples of traction transport include the movement of pebbles or rocks along a riverbed due to the force of the flowing water.
All of the above:
- The answer choice "All of the above" (option D) is correct because transport within the transporting medium can occur through suspension, solution, and traction.
- Depending on the specific conditions and characteristics of the transporting medium, one or more of these transport mechanisms may be present.
In conclusion, transport within the transporting medium can occur by suspension, solution, and traction. These different mechanisms allow for the movement of solid particles, dissolved substances, and larger particles within a fluid medium.

The islands with coral covered surfaces in Bay of Bengal are:
- Andaman islands: The Andaman islands are known for their rich coral ecosystems. These islands are home to a diverse range of coral species and offer excellent opportunities for snorkeling and diving.
- Nicobar islands: Like the Andaman islands, the Nicobar islands also have coral-covered surfaces. These islands are located further south in the Bay of Bengal and are known for their pristine coral reefs.
- Both (a) and (b): The correct answer is both the Andaman islands and the Nicobar islands. Both these island groups have coral-covered surfaces and are famous for their vibrant coral ecosystems.
- None of the above: This option is not correct as both the Andaman islands and the Nicobar islands have coral reefs and are known for their coral-covered surfaces.
In conclusion, the islands with coral-covered surfaces in the Bay of Bengal are the Andaman islands and the Nicobar islands. These islands offer a unique opportunity to explore and experience the beauty of coral reefs.

The length of the day is determined in:


Astronomical units:
- The length of the day is determined by the rotation of the Earth on its axis in relation to the position of the Sun.
- Astronomical units are used to measure distances in space, not the length of the day.
Solar terms:
- Solar terms are used in traditional East Asian calendars to mark the changing of seasons and the positioning of the Sun.
- While solar terms are related to the Sun, they do not directly determine the length of the day.
Length of the hours:
- The length of the day is not determined by the length of the hours.
- The length of an hour is a human construct and can vary depending on the timekeeping system used.
None of the above:
- The correct answer is not "none of the above."
- The length of the day is determined by the Earth's rotation in relation to the Sun, which is measured in solar days.
Therefore, the correct answer is A: astronomical units.

The hot, dry wind on the east or leeward side of the Rocky mountains (North America) is called the Chinook.
Explanation:
- The hot, dry wind that occurs on the east or leeward side of the Rocky Mountains in North America is known as the Chinook.
- The Chinook wind is a warm, downslope wind that occurs when air descends rapidly on the leeward side of the mountains.
- This wind is common in the winter and spring months and can cause a rapid increase in temperature, often melting snow and ice rapidly.
- The Chinook wind is also known as the "snow eater" due to its ability to rapidly melt snow and ice.
- This wind is a localized phenomenon that mainly affects the regions near the Rocky Mountains, including parts of Canada and the United States.
- The Chinook wind can have a significant impact on the local climate, causing temperature fluctuations and affecting weather patterns in the affected areas.
- The Chinook wind is an important aspect of the regional climate and has both positive and negative effects on the environment and human activities in the area.
- Overall, the Chinook wind plays a significant role in shaping the weather and climate on the leeward side of the Rocky Mountains.

The island of Sri Lanka formerly known as:

• Madagascar: Sri Lanka is not formerly known as Madagascar. Madagascar is a separate island country located off the southeast coast of Africa.


• Tasmania: Sri Lanka is not formerly known as Tasmania. Tasmania is an island state of Australia located south of the mainland.


• Ceylon: Correct answer. Sri Lanka was formerly known as Ceylon. The name Ceylon was used during the British colonial period, and Sri Lanka officially changed its name to Sri Lanka in 1972.


• None of the above: Sri Lanka is formerly known as Ceylon, so the correct answer is not "None of the above."

Therefore, the correct answer is Ceylon.

Location of Seychelles
- The islands of Seychelles are located in the Indian Ocean.
- Seychelles is an archipelago comprising 115 islands, located off the eastern coast of Africa.
- The country is situated northeast of Madagascar and about 1,600 kilometers (994 miles) east of mainland Africa.
- It is positioned between latitudes 4°S and 10°S and longitudes 46°E and 55°E.
Geographical Features
- Seychelles is known for its stunning beaches, crystal-clear waters, and diverse marine life.
- The islands are characterized by lush tropical vegetation, granite rock formations, and coral reefs.
- The largest islands in Seychelles are Mahé, Praslin, and La Digue.
- The capital city, Victoria, is located on the largest island, Mahé.
Climate and Natural Resources
- Seychelles has a tropical climate, with warm temperatures throughout the year.
- The country experiences two main seasons: a dry season from May to October and a wet season from November to April.
- Seychelles is rich in natural resources, including fish, coconuts, cinnamon, vanilla, and various fruits.
Importance of the Indian Ocean
- The Indian Ocean is the third-largest ocean in the world and plays a significant role in global trade, transportation, and marine biodiversity.
- It is a major route for international shipping and connects various countries in Africa, Asia, and Oceania.
- The Indian Ocean region is home to a wide range of marine species, including coral reefs, fish, whales, and dolphins.
Tourism in Seychelles
- The location of Seychelles in the Indian Ocean, combined with its natural beauty and pristine beaches, makes it a popular tourist destination.
- Tourism is a vital sector for the economy of Seychelles, attracting visitors from around the world to explore its islands, enjoy water sports, and experience the unique flora and fauna.
In conclusion, the islands of Seychelles are located in the Indian Ocean, and their geographical features, climate, and natural resources make them an attractive destination for tourism. The Indian Ocean's significance in global trade and marine biodiversity further enhances the country's importance.

The knowledge about the topography of the ocean basins has been derived from various scientific techniques and instruments. These include:
1. Seismic surveying:
- Seismic surveying involves the use of seismic waves to map the structure of the Earth's subsurface, including the ocean basins.
- Seismic waves are generated by artificial sources, such as air guns or explosives, and the reflections and refractions of these waves can provide information about the underlying topography.
- By analyzing the travel times and amplitudes of the seismic waves, scientists can create detailed maps of the ocean basins.
2. Echo sounder:
- Echo sounders, also known as sonar systems, are used to measure the depth of the ocean floor.
- They work by emitting a sound signal and measuring the time it takes for the signal to bounce back from the seafloor.
- This information is then used to determine the water depth and create bathymetric maps of the ocean basins.
3. Side-scan sonar:
- Side-scan sonar is a specialized type of sonar that provides high-resolution images of the seafloor.
- It uses sound waves to create detailed acoustic images of the ocean floor, allowing scientists to identify features such as ridges, trenches, and underwater volcanoes.
4. All of the above:
- All of these techniques, seismic surveying, echo sounder, and side-scan sonar, are used in combination to gather comprehensive knowledge about the topography of the ocean basins.
- Each technique provides unique information and contributes to our understanding of the underwater landscape.
In conclusion, the knowledge about the topography of the ocean basins has been derived from seismic surveying, echo sounder, and side-scan sonar. These techniques complement each other and enable scientists to create detailed maps and images of the ocean floor.