UPSC Prelims 2011 Analysis

Explanation

The lower deltaic plains of the Ganges and Brahmaputra rivers are characterized by swamps and Sundarbans

Paddy (rice) The lower Gangetic plain has a humid climate with high temperatures and fertile alluvial soil, which are ideal conditions for growing rice. Rice is a staple food crop in India and this region is a major producer.

Jute Jute is a fiber crop that thrives in warm and humid climates with ample water. The riverine delta of the Ganges provides the necessary moisture and fertile land for jute cultivation. India is a leading producer of jute, and a significant portion comes from the lower Gangetic plain.

Other crops like wheat and cotton might not be as suitable due to the year-round high temperatures. While wheat prefers cooler winters, cotton requires drier conditions.

Explanation

The state in India with the characteristics described is Gujarat

Northern Arid and Semi-Arid The northern part of Gujarat, bordering Rajasthan, experiences a dry climate.

Central Cotton Production Gujarat is a major producer of cotton in India, and the central part of the state is known for its cotton cultivation.

Cash Crop Predominance Gujarat's agricultural sector focuses heavily on cash crops like cotton, groundnut, and castor oilseed, compared to food crops like rice and wheat.

Explanation

La Nina and El Nino are both part of the El Nio-Southern Oscillation (ENSO) cycle, which affects weather patterns around the world. La Nina is characterized by unusually cold ocean temperatures in the Equatorial Pacific, not the Indian Ocean as stated in statement 1. Therefore, statement 1 is incorrect. On the other hand, El Nino is characterized by unusually warm ocean temperatures in the Equatorial Pacific. Regarding statement 2, both El Nino and La Nina have effects on the monsoon climate. El Nino tends to weaken the monsoon, leading to drought conditions in India, while La Nina tends to strengthen the monsoon, leading to above-normal rainfall. Therefore, statement 2 is also incorrect.

Explanation

The "U" turn made by the Brahmaputra River in its course to flow into India is primarily due to the geological phenomenon known as "syntaxial bending" of the geologically young Himalayas.

Syntaxial bending refers to the bending or folding of rock layers that occurs as a result of the collision and convergence of tectonic plates. In the case of the Brahmaputra River, the collision of the Indian Plate with the Eurasian Plate has resulted in the uplift of the Himalayas and the bending of the river's course.

The Brahmaputra River flows from Tibet into India, and as it encounters the geologically young Himalayas, it undergoes a sharp bend in its course, forming the characteristic "U" shape.

Explanation

India is regarded as a country with a "demographic dividend" due to its large working-age population compared to its dependent population (young and old).

Working-age population This refers to the population segment that is traditionally in the workforce, typically between the ages of 15 and 64. Dependent population This includes children (usually below 15 years) and older adults (usually above 64 years) who are financially reliant on the working-age population.

A large working-age population relative to the dependent population creates a potential for economic growth. This is because more people are contributing to the economy through their labour and taxes, while fewer are relying on social services.

Explanation

Statement 1 (Correct) Micro-irrigation delivers water directly to the plant's root zone, minimizing evaporation and water wastage. This allows for a more targeted application of fertilizers and nutrients, reducing their loss in the soil.

Statement 2 (Incorrect) While micro-irrigation is very efficient in water usage, it's not the only option for dryland farming. Other methods like drip irrigation or rainwater harvesting can also be used.

Statement 3 (Correct) Micro-irrigation uses less water compared to traditional methods like flood irrigation. This can help conserve groundwater resources and potentially slow down the receding water table in some areas, depending on the specific water management practices employed.

Explanation

Analysis

• Major rivers flowing into the Bay of Bengal from Jharkhand are the Subarnarekha and North Koel.
• The Subarnarekha changes its name to Brahmani in Odisha.
• The Brahmani merges with the Baitarani river, which originates in Odisha.
• The confluence of Brahmani and Baitarani forms the delta that feeds into the Bay of Bengal.
• Bhitarkanika National Park is a protected area located in this delta region, known for its rich wildlife and biodiversity, particularly saltwater crocodiles.

Explanation

The westerlies in the southern hemisphere are indeed stronger and more persistent than in the northern hemisphere.

This is primarily due to the fact that the southern hemisphere has less landmass compared to the northern hemisphere. The vast expanses of open ocean in the southern hemisphere allow the westerlies to maintain their strength and persistence without being interrupted by landmasses.

On the other hand, the Coriolis force, which is a result of Earth's rotation, is not stronger in the southern hemisphere compared to the northern hemisphere. The strength of the Coriolis force is not determined by the hemisphere, but by the latitude. The Coriolis force is strongest at the poles and weakest at the equator.

Therefore, only Statement 1 is true.

Explanation

The Ionosphere is a layer in the Earth's atmosphere that is ionised by solar radiation. It plays a crucial role in radio communication as it reflects radio waves back to Earth. This reflection is not due to the presence of ozone but rather due to the ionisation of atoms in the Ionosphere. Therefore, statement 1 is incorrect.

As for statement 2, while it is true that radio waves have a long wavelength, this is not the reason why the Ionosphere facilitates radio communication. The reflection of radio waves by the Ionosphere is due to the ionisation of atoms, not the wavelength of the radio waves. Therefore, statement 2 is also incorrect.

Explanation

Arunachal Pradesh is located in northeastern India and is known for its favourable climatic conditions, which make it an ideal place for orchid cultivation.

The state is home to over 600 species of orchids, which account for about 52% of all orchid species in India. The state's abundant rainfall and suitable temperatures contribute to lower production costs compared to other states.

Arunachal Pradesh has the potential to develop an export-oriented industry in orchid cultivation and tap into international markets by focusing on quality production and marketing strategies.

Explanation

The Kra Isthmus is the narrowest part of the Malay Peninsula, located in Thailand. Opening a new canal across this isthmus would create a direct sea route between the Gulf of Siam and the Andaman Sea, bypassing the longer route around the southern tip of Malaysia through the Malacca Straits. This would also greatly reduce the navigation time and distance between India and East Asia. Therefore, statement 2 is also correct. Malacca Strait is the main shipping channel between the Indian Ocean and the Pacific Ocean and links India, China, Japan, and South Korea. The issue of deepening of the Malacca Strait is linked to its economic importance rather than time of navigation and distance.

Explanation

The tropical rainforest is a complex ecosystem with a high level of biodiversity. When a tropical rainforest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is primarily due to the fact that the soil of the rainforest is deficient in nutrients. The high rainfall in these areas washes away the nutrients from the soil, making it less fertile. The other options, such as poor viability of propagules, slow-growing species, and invasion by exotic species, may also contribute to the slow regeneration, but the primary reason is the nutrient-deficient soil.

Explanation

Commercial jet aircraft fly in the lower stratosphere to avoid the turbulence.

The Stratosphere is very dry; air there contains very little water vapour. Because of this, few clouds are found in this layer.

Vertical wind shear is a change in wind speed or direction with change in altitude.

Wind shear has significant effects on control of an aircraft, and it has been a sole or contributing cause of many aircraft accidents.

There is no vertical wind shear in the lower stratosphere. That's why planes fly in that region to avoid turbulence or an accident.

Explanation

The African and Eurasian desert belt is primarily formed due to its location in the sub-tropical high-pressure cells. These high-pressure areas are characterised by descending air, which is dry and leads to arid conditions, forming deserts.

However, the influence of warm ocean currents is not a significant factor in the formation of these desert belts. Warm ocean currents generally increase the moisture content in the air, leading to more precipitation, not desert conditions.

Therefore, the correct answer is that the desert belt is located in the sub-tropical high-pressure cells.