Q21moderateCommon Misconception
Consider the following statements:
Statement-I: India, despite having uranium deposits, depends on coal for most its electricity production.
Statement-II: Uranium, enriched to the extent of at least 60%, is required for the production of electricity.
Which one of the following is correct in respect of the above statements?
(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
(b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
(c) Statement-I is correct but Statement-II is incorrect
(d) Statement-I is incorrect but Statement-II is correct
Answer: (c)
Trap: Common Misconception
Statement-II is the trap. Nuclear power plants use Low Enriched Uranium (LEU) at 3-5% enrichment, NOT 60%. The 60% figure is closer to weapons-grade enrichment. Aspirants who don't know the exact enrichment levels may assume higher enrichment is needed for electricity.
Q26moderateCommon Misconception
Consider the following statements:
1. Some mushrooms have medicinal properties.
2. Some mushrooms have psycho-active properties.
3. Some mushrooms have insecticidal properties.
4. Some mushrooms have bioluminescent properties.
How many of the above statements are correct?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Answer: (d)
Trap: Common Misconception
Statements 3 and 4 are potential traps. Many aspirants may not know about insecticidal mushrooms (e.g., Metarhizium-based biopesticides from fungi) or bioluminescent mushrooms (e.g., Mycena chlorophos, ghost mushrooms). Aspirants comfortable with only statements 1 and 2 might choose (b).
Q28moderateCommon Misconception
Consider the following statements:
1. Some microorganisms can grow in environments with temperature above the boiling point of water.
2. Some microorganisms can grow in environments with temperature below the freezing point of water.
3. Some microorganisms can grow in highly acidic environment with a pH below 3.
How many of the above statements are correct?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (c)
Trap: Common Misconception
Aspirants may doubt Statements 1 and 2, thinking no life can survive above 100°C or below 0°C. Hyperthermophiles (archaea near hydrothermal vents) grow above 100°C. Psychrophiles grow below 0°C. Acidophiles thrive at pH < 3. The trap is doubting the extremes and choosing (a) or (b).
Q58moderateCommon Misconception
Consider the following heavy industries:
1. Fertilizer plants
2. Oil refineries
3. Steel plants
Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (d)
Trap: Common Misconception
The official answer (d) is highly disputed. Green hydrogen IS expected to play a significant role in all three industries: as feedstock in fertilizers (replacing grey hydrogen), in oil refineries (for desulfurization), and in steel making (replacing coking coal in DRI). Most experts believe (c) All three is the correct answer.
Q76easy
'Wolbachia method' is sometimes talked about with reference to which one of the following?
(a) Controlling the viral diseases spread by mosquitoes
(b) Converting crop residues into packing material
(c) Producing biodegradable plastics
(d) Producing biochar from thermo-chemical conversion of biomass
Answer: (d)
Q78hardSimilar Sounding
'Aerial metagenomics' best refers to which one of the following situations?
(a) Collecting DNA samples from air in a habitat at one go
(b) Understanding the genetic makeup of avian species of a habitat
(c) Using air-borne devices to collect blood samples from moving animals
(d) Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies
Answer: (c)
Trap: Similar Sounding
The official answer (c) is disputed. 'Aerial metagenomics' most logically refers to collecting and analyzing DNA from air samples (option a) -- eDNA from airborne particles. Option (b) is a trap because 'aerial' sounds like it could relate to 'avian.' Most scientists would define aerial metagenomics as option (a).
Q79easy
'Microsatellite DNA' is used in the case of which one of the following?
(a) Studying the evolutionary relationships among various species of fauna
(b) Stimulating 'stem cells' to transform into diverse functional tissues
(c) Promoting clonal propagation of horticultural plants
(d) Assessing the efficacy of drugs by conducting series of drug trials in a population
Answer: (a)
Q82moderateOutdated Info
Consider the following statements:
1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.
2. Carbon fibres once used cannot be recycled.
Which of the statements give above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (c)
Trap: Outdated Info
The official answer (c) marks Statement 2 as correct, but carbon fibre recycling technologies DO exist (pyrolysis, solvolysis). Several companies recycle carbon fibres. However, UPSC may consider that widespread commercial recycling is not yet viable, or that the recycled product loses significant quality. Aspirants who know about recycling tech may choose (a).
Q83moderateCommon Misconception
Consider the following actions:
1. Detection of car crash/collision which results in the deployment of airbags almost instantaneously.
2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive
3. Detection of the tilt of smartphone which results in the rotation of display between portrait and landscape mode
In how many of the above actions is the function of accelerometer required?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (a)
Trap: Common Misconception
The official answer (a) is highly disputed. All three actions use accelerometers: airbag deployment sensors, laptop free-fall detection (used in ThinkPads), and smartphone screen rotation ALL use accelerometers. The gyroscope assists in rotation but the accelerometer is fundamental. Most experts believe (c) All three is correct.
Q84easyPartial Truth
With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements:
1. Biofilters provide waste treatment by removing uneaten fish feed.
2. Biofilters convert ammonia present in fish waste to nitrate.
3. Biofilters increase phosphorus as nutrient for fish in water.
How many of the statements given above are correct?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (c)
Trap: Partial Truth
The official answer (c) 'all three' is debatable. Statement 2 is clearly correct (nitrification: ammonia to nitrite to nitrate). Statement 1 is partially correct (mechanical filtration removes feed, biofilters handle dissolved waste). Statement 3 is questionable -- biofilters don't typically increase phosphorus; rather, phosphorus management in RAS is a separate challenge. Many experts believe only 1-2 statements are correct.
Q85moderateDistractor Pairing
Consider the following pairs:
Objects in space : Description
1. Cepheids : Giant clouds of dust and gas in space
2. Nebulae : Stars which brighten and dim periodically
3. Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse
How many of the above pairs are correctly matched?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (b)
Trap: Distractor Pairing
Pairs 1 and 2 are SWAPPED. Cepheids are variable stars that brighten and dim periodically (not dust clouds). Nebulae are giant clouds of dust and gas (not variable stars). Aspirants who know both terms but don't carefully match them will mark all three as correct.
Q86easy
Which one of the following countries has its own Satellite Navigation System?
(a) Australia
(b) Canada
(c) Israel
(d) Japan
Answer: (a)
Q87easy
Consider the following statements:
1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight.
2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (d)
Q89moderateAbsolute Qualifier
With reference to green hydrogen, consider the following statements:
1. It can be used directly as a fuel for internal combustion.
2. It can be blended with natural gas and used as fuel for heat or power generation.
3. It can be used in the hydrogen fuel cell to run vehicles.
How many of the above statements are correct?
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (b)
Trap: Absolute Qualifier
The official answer (b) suggests only two are correct. However, all three statements are factually correct: hydrogen CAN be used in internal combustion engines (BMW has tested this), CAN be blended with natural gas, and CAN power fuel cells. Most experts believe (c) is the correct answer. The trap may be Statement 1 -- UPSC may consider that green hydrogen isn't practically used for IC engines.