Ans (a) ֍The Indus originates in the northern slopes of the Kailash range in Tibet near Lake Manasarovar. It follows a north westerly course through Tibet. It enters Indian territory in Jammu and Kashmir. ֍ The main tributaries of the Indus in India are Jhelum, Chenab, Ravi, Beas and Sutlej. ֍ Jhelum and Ravi join Chenab ֍ Beas joins Sutlej and then Sutlej and Chenab join to form Panjnad, 10 miles north of Uch Sharif in Muzaffar Garh district. The combined stream runs southwest for approximately 44 miles and joins the Indus River at Mithankot.

Ans (d) ֍ Didwana, Kuchaman, Sargol and Khatu are names of towns with or near saline lakes. ֍ Didwana is a town in the Nagaur district of Rajasthan. It also has a famous Didwana salt-water lake of Rajasthan. ֍ Kuchaman lake occupies an area of about 8.5 sq. kms in Nagaur District of Rajasthan. ֍ Saline Water Lakes of Rajasthan : Sambhar Salt Lake, Panchpadra Lake(Bikaner), Lunkaransar Lake, Kuchaman (Nagaur) , Tal Chappar (Churu), Degana (Nagaur), Phalodi (Jodhpur), and Kavod (Jaisalmer).

Ans (b) Rivers originating on the Eastern Ghats include: • Baitarani River • Budhabalanga River • Rushikulya River • Vamsadhara River • Palar River • Nagavali River • Champavathi River • Gosthani River • Sarada River • Sabari River • Sileru River • Tammileru • Gundlakamma River • Pennai Yaru River • Swarnamukhi • Kundu River • Vellar River Penna River Nagavali River flows in north eastern Andhra Pradesh and southern Odisha. The origin of Nagavali River lies in the eastern slopes of the Eastern Ghats near Lakhbahal, located at an altitude of 1,300 metres in the Kalahandi district of Odisha. Hence option 2 is correct. Vamsadhara river rises in the Eastern Ghats on the border Kalahandi district and Rayagada district of Odisha. It runs for a distance of about 254 kilometers, where it joins the Bay of Bengal at Kalingapatnam, Andhra Pradesh. Hence option 4 is correct. Brahmani is a major seasonal river in Odisha . The Brahmani is formed by the confluence of the Sankh and South Koel rivers near the major industrial town of Rourkela. The Sankh has its origins near the Jharkhand -Chhattisgarh border. The South Koel too arises in Jharkhand, near Lohardaga, on the other side of a watershed that also gives rise to the Damodar River. Both of these sources are in the Chota Nagpur Plateau. Hence, option 1 is not correct. Subarnarekha River flows through the states of Jharkhand, West Bengal and Odisha. After originating near Ranchi it traverses a long distance through Ranchi and East Singhbhum. Thereafter, it flows for shorter distances through West Bengal and Odisha before joining the Bay of Bengal. Hence, option 3 is not correct.

Ans (a) It takes about 210 litres of water to produce 1 kg of sugar cane. Water footprint of sunflower is 7– 9 litre per kg. Millets are sown in dry areas with minimal irrigation. Red gram requires 35 to 40 cm water, during its entire growth period. As Red gram is a rain-fed crop grown in assured rainfall areas, usually it does not need any irrigation. Hence option (a) is the correct answer.

Ans (c) Warmer water is transported westward in the ocean by the trade winds in tropical zones. In temperate zones, westerlies make the eastern section of the ocean warmer than the western sections.

Ans (d) The tropical rainforest is a hot, moist biome found near Earth’s equator. The hot and humid conditions make tropical rainforests an ideal environment for bacteria and other microorganisms. Because these organisms remain active throughout the year, they quickly decompose matter on the forest floor. In other biomes, such as the deciduous forest, the decomposition of leaf litter adds nutrients to the soil. But in the tropical rainforest, plants grow so fast that they rapidly consume the nutrients from the decomposed leaf litter. As a result, most of the nutrients are contained in the trees and other plants rather than in the soil. Most nutrients that are absorbed into the soil are leached out by the abundant rainfall, which leaves the soil infertile and acidic. Epiphytes are plants which live on the branches of trees high up in the canopy. They get their nutrients from the air and water, not from the soil. Epiphytes are found throughout rainforests.

Ans (c) Savanna ecosystems are heterogeneous environments characterized by the presence of trees, bushes, and grasses. Nutrient and soil moisture availability are usually the limiting factors affecting the biomass growth in savannas, and overall biomass is impacted by competition, fire, grazing, and harvesting. Savanna grassland soils are not very fertile. The nutrients in the soil are found near the surface as they come from decayed organic matter (vegetation) from the previous growing season. This organic matter decays rapidly due to the high temperatures. In the parched grasslands and savannas, or drylands, of Africa, South America and Asia, termite mounds store nutrients and moisture and via internal tunnels, allow water to better penetrate the soil. Herbivory and burrowing activities can reduce overall plant biomass associated with burrowing mammal colonies, but the higher levels of soil nutrients and greater degree of water infiltration that occurs around their mounds can result in elevated foliar nutrient concentrations and greater plant biomass surrounding their burrows. In general, savannas grow in tropical regions 8° to 20° from the Equator. Conditions are warm to hot in all seasons, but significant rainfall occurs for only a few months each year—about October to March in the Southern Hemisphere and April to September in the Northern Hemisphere. Due to limited rainfall, it is characterized by an open tree canopy

Ans (b)

Ans (b) Black soils are mineral soils which have a black surface horizon, enriched with organic carbon that is at least 25 cm deep. Black soil is formed due to the weathering or erosion of the basalt rocks. Basalt is an aphanitic extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface. The black soil in India is found in the states like Maharashtra, Gujarat, Madhya Pradesh, and Karnataka.