The 2020 Codex
Questions 91 to 100 (Set A)
What are the advantages of fertigation in agriculture?
1. Controlling the alkalinity of irrigation water is possible.
2. Efficient application of Rock Phosphate and all other phosphatic fertilizers is possible.
3. Increased availability of nutrients to plants is possible.
4. Reduction in the leaching of chemical nutrients is possible.
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (c) 1, 3 and 4 only
Fertigation is the precise application of dissolved fertilizers through an irrigation system (like drip irrigation).
- Statement 1 is True: Because you are injecting chemicals directly into the water stream, you can inject acids to control water alkalinity and pH levels instantly.
- Statement 2 is False: Fertigation REQUIRES highly water-soluble fertilizers. Rock Phosphate is an extremely insoluble mineral. It will not dissolve in water and will instantly clog the micro-drip emitters.
- Statements 3 & 4 are True: Because nutrients are delivered directly to the root zone in exact micro-doses with the water, nutrient availability increases dramatically and deep percolation/leaching of excess chemicals into groundwater is severely reduced.
The Liquid Diet
The Miner's Ledger
Consider the following minerals:
1. Bentonite
2. Chromite
3. Kyanite
4. Sillimanite
In India, which of the above is/are officially designated as major minerals?
The Secret Whisper
Official Key: (d) 2, 3 and 4 only
The Mines and Minerals (Development and Regulation) Act classifies minerals. This question tests a specific notification published in 2015 where the government shifted several minerals to the 'minor' list to devolve auction powers to states.
Bentonite is specifically listed as a minor mineral (along with building stones, gravel, ordinary clay, ordinary sand). The other three—Chromite, Kyanite, and Sillimanite—are industrial/strategic and remain classified as major minerals.
Route: [REALM 127: Mining Governance & Law] & [REALM 58: Non-Metallic Minerals]With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct?
1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the south-western Indian Ocean during January-March.
2. OMT collected during January-March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean.
Which of the statements given above is/are correct?
The Secret Whisper
Official Key: (b) 2 only
This question was based on a prominent study published in Nature Communications comparing OMT with Sea Surface Temperature (SST) for predicting the Indian monsoon.
Statement 1 is False: While OMT is measured up to the depth of the 26°C isotherm, the actual depth of this isotherm in the south-western Indian Ocean is roughly 59 meters, not 129 meters. (UPSC loves altering deep specific data points).
Statement 2 is True: The core finding of the study was that measuring the thermal energy of the deeper ocean (OMT) during January-March provides an 80% success rate in predicting the summer monsoon rainfall (whether it will be above or below the long-term mean), compared to just 60% for surface temperature (SST).
Route: [REALM 14: Indian Monsoon] & [REALM 10: Ocean Temperatures]The Thermal Depth
The Subsidized Sack
With reference to chemical fertilizers in India, consider the following statements:
1. At present, the retail price of chemical fertilizers is market-driven and not administered by the Government.
2. Ammonia, which is an input of urea, is produced from natural gas.
3. Sulphur, which is a raw material for phosphoric acid fertilizer, is a by-product of oil refineries.
Which of the statements given above is/are correct?
The Secret Whisper
Official Key: (b) 2 and 3 only
This covers the fertilizer sector's raw materials and policy.
Statement 1 is False: Urea is the most consumed fertilizer in India, and its Maximum Retail Price (MRP) is statutorily fixed (administered) by the Government of India. It is heavily subsidized and absolutely not market-driven.
Statement 2 is True: The primary raw material used to produce Ammonia (the core building block of Urea) is Natural Gas (methane), which provides the necessary hydrogen for the Haber process.
Statement 3 is True: A major source of industrial Sulphur globally is the desulfurization process at petroleum/oil refineries, which extract sulphur from crude oil. This sulphur is then used to make sulfuric acid, which is required to process phosphate rock into phosphoric acid fertilizers.
Route: [REALM 12: Agri Inputs & Infrastructure] & [REALM 148: Petrochemical Industries]With reference to India's Desert National Park, which of the following statements are correct?
1. It is spread over two districts.
2. There is no human habitation inside the Park.
3. It is one of the natural habitats of Great Indian Bustard.
Select the correct answer using the code given below:
The Secret Whisper
Official Key: (c) 1 and 3 only
The Desert National Park is an enormous, fragile ecosystem situated in the Thar Desert of Rajasthan.
Statement 1 is True: It is one of the largest national parks in India (over 3162 sq km) and is spread across two distinct districts: Jaisalmer and Barmer.
Statement 2 is False: Unlike highly strict core zones in other parks, the Desert National Park has over 70 villages and numerous scattered human habitations directly inside its boundary, leading to complex conservation challenges.
Statement 3 is True: It is the last major stronghold and natural habitat for the critically endangered Great Indian Bustard (GIB), which is heavily threatened by hunting and high-voltage power lines.
Route: [REALM 93: Protected Areas] & [REALM 106: Critically Endangered Fauna]The Thar Sanctuary
The Roof of the World
Siachen Glacier is situated to the
The Secret Whisper
Official Key: (d) North of Nubra Valley
This requires precise mental mapping of the Ladakh/Karakoram region:
- Aksai Chin is in the far east of the Ladakh region. Siachen is to its West, not East.
- Leh is located centrally in Ladakh. Siachen is far to its North/North-West, not East.
- Gilgit is in PoK, to the west of Siachen. Siachen is to the East of Gilgit, not North.
- Nubra Valley is carved out by the Nubra River, which literally originates from the snout of the Siachen Glacier. Therefore, the Siachen Glacier lies exactly North of the Nubra Valley.
With reference to the history of India, consider the following pairs:
| Famous Place | Present State |
|---|---|
| 1. Bhilsa | Madhya Pradesh |
| 2. Dwarasamudra | Maharashtra |
| 3. Girinagar | Gujarat |
| 4. Sthanesvara | Uttar Pradesh |
Which of the pairs given above are correctly matched?
The Secret Whisper
Official Key: (a) 1 and 3 only
Let's map these ancient historical capitals to their modern-day states:
- 1. Bhilsa (Vidisha): An ancient city located in present-day Madhya Pradesh, famous for the Heliodorus pillar. (Correct)
- 2. Dwarasamudra (Halebidu): The glorious capital of the Hoysala Empire, it is located in present-day Karnataka, not Maharashtra. (False)
- 3. Girinagar (Junagadh/Girnar): The ancient city famous for the inscriptions of Ashoka and Rudradaman, located in Saurashtra, Gujarat. (Correct)
- 4. Sthanesvara (Thanesar): The original capital of the Pushyabhuti dynasty (Harshavardhana) before he moved to Kannauj. Thanesar is located in present-day Kurukshetra, Haryana, not Uttar Pradesh. (False)
The Ghost Capitals
The Thirsty Earth
Consider the following statements:
1. 36% of India's districts are classified as "overexploited" or "critical" by the Central Ground Water Authority (CGWA).
2. CGWA was formed under the Environment (Protection) Act.
3. India has the largest area under groundwater irrigation in the world.
Which of the statements given above is/are correct?
The Secret Whisper
Official Key: (b) 2 and 3 only
Statement 1 is False: This is a statistical exaggeration trap by UPSC. While India's groundwater situation is dire, at the time of the question, the CGWA assessment classified roughly 16-17% of assessment units (blocks/talukas/mandals, not districts) as over-exploited, not 36% of all districts.
Statement 2 is True: The Central Ground Water Authority (CGWA) was constituted under sub-section (3) of Section 3 of the Environment (Protection) Act, 1986 to regulate and control groundwater development.
Statement 3 is True: Driven by the Green Revolution's reliance on tube-wells, India extracts more groundwater for irrigation than China and the USA combined, giving it the largest area under groundwater irrigation globally.
Route: [REALM 118: Water Resources Degradation] & [REALM 198: Environmental Institutions]Consider the following statements:
1. Jet streams occur in the Northern Hemisphere only.
2. Only some cyclones develop an eye.
3. The temperature inside the eye of a cyclone is nearly 10°C lesser than that of the surroundings.
Which of the statements given above is/are correct?
The Secret Whisper
Official Key: (c) 2 only
Statement 1 is False ("only" trap): Jet streams are fast-flowing, narrow air currents found in the tropopause. They exist in both the Northern and Southern Hemispheres (Polar and Sub-tropical jet streams).
Statement 2 is True: The "Eye" is a region of mostly calm weather found at the center of strong tropical cyclones. Extra-tropical (temperate) cyclones do not develop an eye. Furthermore, even weak tropical cyclones (depressions/storms) lack a well-defined eye.
Statement 3 is False: This is a thermodynamic inversion. The eye of a mature tropical cyclone features sinking air that warms by compression. Thus, the temperature inside the eye is actually significantly warmer (often by several degrees, not 10°C lesser) than the surrounding towering cumulonimbus eyewall.
Route: [REALM 11: Atmospheric Circulation] & [REALM 13: Tropical Cyclones]The Warm Core
The Sovereign Core
Among the following Tiger Reserves, which one has the largest area under "Critical Tiger Habitat"?
The Secret Whisper
Official Key: (c) Nagarjunsagar-Srisailam
The "Critical Tiger Habitat" refers to the absolutely inviolate 'Core Area' of a tiger reserve where forestry operations and human interference are prohibited under the Wildlife Protection Act.
While Sunderbans and Corbett are extremely famous, Nagarjunsagar-Srisailam Tiger Reserve (NSTR) in Andhra Pradesh is geographically the largest tiger reserve in India. Consequently, its designated core area (Critical Tiger Habitat) is also the largest among all Indian tiger reserves, spanning roughly 2595 sq km. (For comparison, Sunderbans core is ~1699 sq km, and Corbett is ~821 sq km).
Route: [REALM 93: Protected Areas] & [REALM 104: Project Tiger]