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General Science and Technology

222 questions

All types222Multiple choice117Multiple select40True / False8Matching44Ordering13
Question 101Question →

Which of the following indigenously developed Indian missiles is classified primarily as a Beyond Visual Range (BVR) Air-to-Air missile?

Show answer & explanation

Answer: Astra

Answer

Astra
Astra is India's premier Beyond Visual Range Air-to-Air Missile (BVRAAM) developed by the Defense Research and Development Organisation (DRDO). It allows fighter aircraft to destroy hostile aerial targets at distances exceeding 100 km.

Step-by-Step Solution

1
Identify the primary role and operational domain of the Astra missile system.
Astra is designed to be integrated onto fighter aircraft (such as Su-30MKI and Tejas) for engaging aerial targets beyond visual range.
Defense categorization differentiates weapons by launch platform and target type (e.g., air-to-air, surface-to-air, anti-tank).

Key Concept

Classification of Indian Indigenous Defense Missiles
Estimated Time:45s
Question 102Question →

Match the chemical compounds in List I with their primary industrial applications and daily life functions in List II.

Click a left item, then click its matching right item

Items

Hydrazine (N2H4N_2H_4)
Sodium Thiosulfate (Na2S2O3Na_2S_2O_3)
Calcium Phosphate (Ca3(PO4)2Ca_3(PO_4)_2)
Zeolite (Hydrated Aluminosilicate)

Matches

Show answer & explanation

Answer

Hydrazine correctly pairs with its industrial role as a boiler water oxygen scavenger and propellant; Sodium Thiosulfate correctly pairs with its application as an antichlor agent and photographic fixer; Calcium Phosphate pairs with its biological role as the structural constituent of tooth enamel and bone; Zeolite pairs with its function as an ion-exchange water softener and catalyst.
Each chemical compound is accurately linked to its specific functional role: Hydrazine acts as an oxygen scavenger in boiler feed water; Sodium Thiosulfate acts as an antichlor and photographic fixer; Calcium Phosphate forms the mineral structure of tooth enamel and bone; Zeolite acts as an ion-exchange medium for water softening.

Step-by-Step Solution

1
Identify the industrial function of Hydrazine (N2H4N_2H_4).
Hydrazine reacts quantitatively with dissolved oxygen to yield nitrogen gas and water, preventing pitting corrosion in steam boilers without increasing dissolved solid content.
Its strong reducing action makes it ideal for water treatment and rocket fuel formulations.
2
Determine the application of Sodium Thiosulfate (Na2S2O3Na_2S_2O_3).
Sodium thiosulfate neutralizes excess chlorine left on textiles post-bleaching (acting as an antichlor) and forms soluble thiosulfato-argentate complexes in film processing.
These chemical reactions define its dual identity as an antichlor and photographic fixing agent ('hypo').
3
Analyze the biochemical structural role of Calcium Phosphate (Ca3(PO4)2Ca_3(PO_4)_2).
In biological systems, crystalline calcium phosphate derivatives (hydroxyapatite) construct the hard mineral phase of bones and dental enamel.
It supplies structural integrity against mechanical stress in mammalian anatomy.
4
Evaluate the chemical utility of Zeolites.
Microporous sodium aluminosilicates exchange their structural Na+Na^+ ions for hard-water Ca2+Ca^{2+} and Mg2+Mg^{2+} ions, making them effective builders in eco-friendly detergents.
Their defined molecular pore networks also allow shape-selective catalytic cracking in petroleum refineries.

Key Concept

Industrial applications and daily life functions of inorganic compounds
Question 103Question →

With reference to cellular organelles and genetic mechanisms in eukaryotic organisms, consider the following statements:

1. Mitochondria and chloroplasts possess their own double-stranded circular DNA and 70S ribosomes, allowing them to synthesize some of their own structural proteins semi-autonomously.
2. Lysosomal hydrolytic enzymes are synthesized primarily by ribosomes on the smooth endoplasmic reticulum and are directly secreted into the cytoplasm without entering Golgi cisternae.
3. Genetic recombination through crossing over during Meiosis I occurs specifically between non-sister chromatids of homologous chromosomes during the pachytene substage of Prophase I.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

Statements 1 and 3 only are correct.
The correct answer states that statements 1 and 3 only are correct. Mitochondria and chloroplasts contain prokaryotic features (70S ribosomes, naked circular DNA) supporting semi-autonomy. Crossing over occurs strictly between non-sister chromatids of homologous chromosomes during pachytene. Statement 2 is false because acid hydrolases in lysosomes are synthesized by the rough endoplasmic reticulum and targeted to lysosomes by the Golgi apparatus.

Step-by-Step Solution

1
Evaluate Statement 1 regarding semi-autonomous organelles.
Statement 1 is correct. Both mitochondria and chloroplasts have their own circular double-stranded DNA molecule and prokaryotic-type 70S ribosomes, replicating independently of the nucleus via binary fission.
Endosymbiotic theory accounts for the bacterial-like genetic apparatus of these organelles.
2
Evaluate Statement 2 regarding lysosome biogenesis.
Statement 2 is incorrect. Lysosomal enzymes (acid hydrolases) are synthesized by ribosomes on the Rough Endoplasmic Reticulum (RER), transported to the cis-face of the Golgi apparatus, tagged with mannose-6-phosphate, and budded off as primary lysosomes from the trans-Golgi network.
Smooth ER is involved in lipid/steroid synthesis and detoxification, not lysosomal protein synthesis.
3
Evaluate Statement 3 regarding meiotic crossing over.
Statement 3 is correct. Crossing over is an enzyme-mediated process (recombinase) occurring between non-sister chromatids of homologous chromosomes at the pachytene stage of Prophase I, forming chiasmata seen in diplotene.
Reciprocal exchange of genetic material between non-sister chromatids creates genetic variation.

Key Concept

Organelle autonomy, lysosome biogenesis, and meiotic genetic recombination
Estimated Time:2m 0s
Question 104Question →

Induction cooktops are increasingly popular in modern households due to their safety and rapid heating capabilities. Which of the following physical principles is primarily responsible for generating heat directly within a ferromagnetic cooking vessel placed on an active induction zone?

Show answer & explanation

Answer: Induced eddy currents and magnetic hysteresis losses generated by a rapidly alternating magnetic field

Answer

Heat is generated directly inside the cookware through induced eddy currents and magnetic hysteresis losses caused by a high-frequency alternating magnetic field.
The correct answer identifies that an induction cooktop utilizes an alternating magnetic field to induce eddy currents and hysteresis losses directly inside the ferromagnetic metal of the vessel, causing rapid Joule heating without heating the stovetop directly.

Step-by-Step Solution

1
Identify the primary electrical component under the induction glass top
A high-frequency alternating current (20–100 kHz20\text{--}100\text{ kHz}) is passed through a copper coil located beneath the cooktop surface.
Passing alternating current through a coil produces a rapidly fluctuating magnetic field according to Ampère's Law and Faraday's Law of Induction.
2
Determine the interaction between the fluctuating magnetic field and the ferromagnetic cookware
The alternating magnetic flux passes through the base of the ferromagnetic pot, inducing closed loops of electrical currents called eddy currents (Foucault currents).
According to Faraday's Law of Electromagnetic Induction, a time-varying magnetic field induces an electromotive force (EMF) in nearby conductive materials.
3
Analyze how heat energy is dissipated inside the vessel material
The electrical resistance of the pot material causes Joule heating (P=I2RP = I^2R) from eddy currents, supplemented by heat generated from magnetic hysteresis in the magnetic domain structures.
Ferromagnetic metals possess high electrical resistance and magnetic hysteresis, causing electrical energy transferred via magnetic field to turn into heat energy within the pot base.

Key Concept

Electromagnetic Induction and Eddy Current Heating in Everyday Technology
Estimated Time:1m 0s
Question 105Question →

Consider the following statements regarding the 'Astra' missile system indigenously developed in India:

1. It is India's first indigenous Beyond-Visual-Range Air-to-Air Missile (BVRAAM).
2. It is powered by a single-stage solid-propellant rocket motor.
3. It features an active radar terminal homing mechanism for guidance.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1, 2, and 3

Answer

All three statements (1, 2, and 3) are correct.
The correct answer includes all three statements because Astra is India's first indigenous Beyond-Visual-Range Air-to-Air Missile (BVRAAM), powered by a single-stage solid-propellant engine, and guided by mid-course inertial navigation combined with active radar terminal homing.

Step-by-Step Solution

1
Analyze Statement 1 regarding missile classification and role.
Statement 1 is correct. Astra Mk-1 is India's first indigenously designed and developed Beyond-Visual-Range Air-to-Air Missile (BVRAAM) capable of engaging enemy aircraft at ranges beyond visual sight.
DRDO developed Astra specifically as an all-weather, day-and-night air-to-air missile asset for fighter aircraft such as Su-30MKI.
2
Analyze Statement 2 regarding propulsion technology.
Statement 2 is correct. Astra uses a smokeless single-stage solid-fuel rocket motor that propels it to supersonic speeds exceeding Mach 4.5.
Solid propellant provides high reliability and immediate readiness essential for air-launched interceptor missiles.
3
Analyze Statement 3 regarding guidance and tracking mechanism.
Statement 3 is correct. The missile uses fiber-optic gyro-based inertial navigation for mid-course guidance and an active radar seeker for terminal homing.
Terminal active radar seeker allows autonomous lock-on capability near the target.

Key Concept

Indigenously developed air-to-air missile platforms (Astra BVRAAM) and their propulsion/guidance systems.
Question 106Question →

Match the chemical substances listed in List I with their corresponding primary industrial applications or daily life functions in List II.

Click a left item, then click its matching right item

Items

Chloroxylenol
Melamine-Formaldehyde Resin
Bordeaux Mixture
Potassium Nitrate

Matches

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Answer

Chloroxylenol matches with active antiseptic agent in commercial disinfectant liquid formulations; Melamine-Formaldehyde Resin matches with thermosetting polymer utilized in manufacturing shatterproof dinnerware; Bordeaux Mixture matches with inorganic fungicide and bactericide applied in agricultural crop protection; and Potassium Nitrate matches with oxidizing component used in gunpowder and pyrotechnic formulations.
Chloroxylenol functions as an active antiseptic in disinfectant liquids; Melamine-Formaldehyde Resin is a thermosetting plastic used for durable dinnerware; Bordeaux Mixture is a copper-based agricultural fungicide; and Potassium Nitrate serves as an oxidizing agent in propellant and pyrotechnic mixtures.

Step-by-Step Solution

1
Analyze the chemical nature and application of Chloroxylenol.
Chloroxylenol (C8H9ClOC_8H_9ClO) is a halogenated phenolic antiseptic.
It disrupts microbial cell membranes and inactivates key cellular enzymes, making it the active ingredient in antimicrobial products.
2
Evaluate the structure and utility of Melamine-Formaldehyde Resin.
It is formed via condensation polymerization of melamine with formaldehyde.
Extensive three-dimensional cross-linking renders it rigid, durable, and heat-resistant, ideal for shatterproof kitchenware.
3
Examine the composition and agricultural role of Bordeaux Mixture.
It is prepared by combining copper sulfate (CuSO4CuSO_4) solution with slaked lime (Ca(OH)2Ca(OH)_2) suspension.
The released copper ions (Cu2+Cu^{2+}) inhibit fungal spore germination on crops such as grapes and potatoes.
4
Identify the industrial function of Potassium Nitrate.
Potassium nitrate (KNO3KNO_3) readily undergoes thermal decomposition to liberate oxygen gas.
This rapid oxygen supply drives the rapid oxidation of fuels (sulfur and charcoal) in gunpowder and pyrotechnic compositions.

Key Concept

Chemical compounds in daily life and industrial applications
Question 107Question →

Regarding India's naval nuclear propulsion and submarine-launched ballistic missile capabilities within its nuclear triad, analyze the following assertions:

Statement I: INS Arihant is powered by an indigenously developed pressurized light-water reactor using enriched uranium fuel.
Statement II: The K-15 (Sagarika) missile is an intercontinental ballistic missile with a operational strike range exceeding 5,000 km5,000\text{ km}.

Which of the statement(s) given above is/are correct?

Show answer & explanation

Answer: Only Statement I

Answer

Only Statement I is correct.
The statement asserting that INS Arihant uses a pressurized light-water reactor with enriched uranium is factually correct. The statement claiming K-15 Sagarika has a range over 5,000 km is incorrect, as its actual range is approximately 750 km.

Step-by-Step Solution

1
Examine the propulsion reactor specifications of INS Arihant.
INS Arihant is powered by a compact 83 MW83\text{ MW} Pressurized Light Water Reactor (PWR) developed by BARC, which uses enriched uranium fuel.
Light water reactors are standard for marine propulsion applications requiring compact reactors.
2
Evaluate the missile designation and operational range of K-15 (Sagarika).
The K-15 Sagarika is a submarine-launched ballistic missile (SLBM) with an effective strike range of around 750 km750\text{ km}, whereas long-range SLBM capabilities are provided by missiles like K-4 (3,500 km3,500\text{ km}).
Attributing an intercontinental range (>5,000 km>5,000\text{ km}) to K-15 is an error in missile range categorization.

Key Concept

Naval Nuclear Propulsion and Submarine Launched Ballistic Missiles (SLBM)
Question 108Question →

Regarding the BrahMos missile system developed jointly by India and Russia, which of the following features are correct?

Select all that apply

Show answer & explanation

Answer: It operates on a 'fire-and-forget' principle requiring no guidance after launch; It can be launched from multi-domain platforms including land, ships, submarines, and aircraft

Answer

The correct statements are that the BrahMos missile operates on a 'fire-and-forget' principle and is capable of multi-platform launch from land, sea, sub-sea, and air.
The BrahMos missile is an indigenously integrated supersonic cruise missile developed by BrahMos Aerospace (a joint venture of DRDO and NPO Mashinostroyeniya). It features high precision with a 'fire-and-forget' navigation system and possesses multi-platform deployment capability across army, navy, and air force divisions.

Step-by-Step Solution

1
Analyze the operational classification and guidance mechanism of BrahMos
BrahMos is a supersonic cruise missile operating on a fire-and-forget principle with high terminal accuracy.
It employs self-contained guidance systems allowing high target hit accuracy.
2
Verify platform deployment versatility
The system has land-based, naval surface, underwater submarine, and air-launched variants.
Joint DRDO and NPO Mashinostroyeniya design specifications engineered multi-platform capability.
3
Evaluate propulsion and missile trajectory classification
It is a tactical supersonic cruise missile powered by a solid booster and liquid ramjet engine, rejecting long-range ballistic missile and nuclear propulsion assertions.
Cruise missiles maintain atmosphere-bound flight powered by air-breathing jet engines.

Key Concept

BrahMos Supersonic Cruise Missile System
Question 109Question →

With reference to chemicals widely used in daily life and food processing, consider the following statements:

1. Sodium benzoate functions as an effective food preservative primarily in acidic conditions by inhibiting microbial growth.
2. Calcium carbide (CaC2CaC_2) releases ethylene gas (C2H4C_2H_4) upon reaction with moisture to artificially ripen fruits.
3. Aspartame decomposes at elevated cooking temperatures, making its use restricted to cold foods and soft drinks.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

Statements 1 and 3 only are correct.
The correct response identifies that statements 1 and 3 are factually accurate. Sodium benzoate operates effectively as a antimicrobial preservative in acidic mediums (pH < 4.5) like soft drinks and pickles. Aspartame decomposes under heat and is strictly used in cold food items. Statement 2 is false because calcium carbide reacts with water to yield acetylene gas (C2H2C_2H_2), not ethylene gas (C2H4C_2H_4).

Step-by-Step Solution

1
Analyze statement 1 regarding Sodium benzoate
Sodium benzoate (C6H5COONaC_6H_5COONa) is converted to benzoic acid in low pH (acidic) environments, which penetrates microbial cells and inhibits cellular enzymes. Statement 1 is correct.
Verify the mechanism and optimal pH conditions for sodium benzoate as a food preservative.
2
Analyze statement 2 regarding Calcium carbide
Calcium carbide (CaC2CaC_2) reacts with atmospheric moisture to produce acetylene gas (C2H2C_2H_2), according to the reaction CaC2+2H2O→Ca(OH)2+C2H2CaC_2 + 2H_2O \rightarrow Ca(OH)_2 + C_2H_2. Acetylene mimics ethylene in ripening, but the gas produced directly is acetylene, not ethylene. Statement 2 is incorrect.
Identify the precise chemical gas liberated by calcium carbide during fruit ripening.
3
Analyze statement 3 regarding Aspartame
Aspartame is a methyl ester of a dipeptide (aspartic acid/phenylalanine). It breaks down at high temperatures, losing its sweet flavor. Thus, it is unsuitable for baking or hot cooking. Statement 3 is correct.
Check thermal stability and culinary applications of artificial sweeteners.

Key Concept

Chemical compounds in food preservation, artificial ripening, and non-nutritive sweeteners
Estimated Time:1m 30s
Question 110Question →

Match List-I (Infectious Human Disease) with List-II (Primary Type of Causative Pathogen) and select the correct answer using the code given below:

List-I
A. Chikungunya
B. Syphilis
C. Leishmaniasis
D. Athlete's Foot

List-II
1. Protozoan parasite
2. Fungal organism
3. Virus
4. Bacterium

Which of the following represents the correct matching code?

Show answer & explanation

Answer: A-3, B-4, C-1, D-2

Answer

The correct matching code is A-3, B-4, C-1, D-2.
The combination assigning Chikungunya to a Virus (3), Syphilis to a Bacterium (4), Leishmaniasis to a Protozoan parasite (1), and Athlete's foot to a Fungal organism (2) accurately reflects the etiology of each disease.

Step-by-Step Solution

1
Identify the pathogen responsible for Chikungunya
Chikungunya is an RNA viral infection transmitted by Aedes mosquitoes (Matches A with 3).
Chikungunya virus belongs to the genus Alphavirus.
2
Identify the pathogen responsible for Syphilis
Syphilis is a sexually transmitted disease caused by the spirochete bacterium Treponema pallidum (Matches B with 4).
Treponema pallidum is a obligate internal bacterial parasite.
3
Identify the pathogen responsible for Leishmaniasis (Kala-azar)
Leishmaniasis is caused by intracellular protozoan parasites of the genus Leishmania transmitted by phlebotomine sandflies (Matches C with 1).
Leishmania species are unicellular eukaryotic protozoans.
4
Identify the pathogen responsible for Athlete's Foot
Athlete's foot (tinea pedis) is a superficial fungal infection affecting the skin of the feet (Matches D with 2).
Dermatophyte fungi such as Trichophyton rubrum break down keratin in outer skin layers.

Key Concept

Classification of Human Pathogens (Viral, Bacterial, Protozoan, Fungal)
Question 111Question →

Which of the following statements regarding human blood components and their functions are correct?

Select all that apply

Show answer & explanation

Answer: Red blood cells (erythrocytes) contain hemoglobin, which is responsible for transporting oxygen to body tissues.; White blood cells (leukocytes) serve as a crucial component of the human immune system to combat infections.

Answer

The correct statements are those identifying red blood cells as oxygen carriers via hemoglobin and white blood cells as key defensive components of the immune system.
Red blood cells carry oxygen using hemoglobin throughout the circulatory system, and white blood cells provide cellular and humoral defense mechanisms against disease. Both of these statements correctly describe human blood physiology.

Step-by-Step Solution

1
Evaluate the statement concerning red blood cells (erythrocytes).
Erythrocytes are rich in hemoglobin and their principal function is oxygen transport from respiratory organs to tissues.
This statement accurately describes erythrocyte physiology.
2
Evaluate the statement concerning blood platelets (thrombocytes).
Platelets function in blood coagulation, while lymphocyte white blood cells secrete antibodies.
Confusing platelet function with lymphocyte immune defense is incorrect.
3
Evaluate the statement concerning white blood cells (leukocytes).
Leukocytes constitute the core cellular defenses of the immune system.
This statement correctly defines leukocyte physiological role.
4
Evaluate the statement concerning blood plasma composition.
Plasma is about 90–92% water with dissolved proteins, whereas cellular components form the rest of whole blood.
Describing plasma as mostly cellular elements misrepresents blood fluid composition.

Key Concept

Composition of Human Blood and Physiological Roles of Formed Elements
Question 112Question →

Match the human digestive enzymes listed in List-I with their primary physiological functions and sites of action listed in List-II:

Click a left item, then click its matching right item

Items

Pepsin
Trypsin
Amylase
Lipase

Matches

Show answer & explanation

Answer

Pepsin matches with initiating protein digestion in the acidic stomach environment; Trypsin matches with cleaving proteins into peptides in the alkaline intestinal environment; Amylase matches with hydrolyzing starch into simple sugars; and Lipase matches with breaking down lipids into fatty acids and glycerol.
Each enzyme is paired correctly based on its substrate and site of physiological action: Pepsin initiates protein digestion in the stomach under acidic conditions; Trypsin continues protein digestion in the small intestine under alkaline conditions; Amylase breaks down complex starches into sugars; and Lipase hydrolyzes fats into fatty acids and glycerol.

Step-by-Step Solution

1
Identify gastric protein-digesting enzymes and their optimal environment.
Pepsin operates in the acidic gastric juice (pH ~1.5–2.0) of the stomach to digest proteins into peptones.
Hydrochloric acid secreted by parietal cells activates pepsinogen into pepsin.
2
Identify intestinal protein-digesting enzymes and their optimal environment.
Trypsin acts in the duodenum/small intestine where pancreatic bicarbonate creates an alkaline pH (~7.5–8.0).
Pancreatic proteases require neutral to slightly alkaline conditions for optimal enzymatic activity.
3
Map carbohydrate and lipid degrading enzymes to their specific substrate reactions.
Amylase acts on carbohydrates (starches), while Lipase acts on lipids (fats).
Enzyme specificity dictates that amylase breaks down α-1,4-glycosidic bonds, whereas lipase hydrolyzes lipid ester bonds.

Key Concept

Human Digestive Enzymes, Substrate Specificity, and pH Requirements
Question 113Question →

Match the cell organelles listed in List-I with their corresponding physiological functions listed in List-II:

Click a left item, then click its matching right item

Items

Mitochondria
Ribosomes
Lysosomes
Golgi Apparatus

Matches

Show answer & explanation

Answer

Mitochondria matches with Cellular respiration and ATP production; Ribosomes matches with Protein synthesis; Lysosomes matches with Intracellular digestion and waste breakdown; Golgi Apparatus matches with Modification, packaging, and sorting of proteins.
Each cell organelle is accurately matched with its essential function: Mitochondria generate cellular energy (ATP), Ribosomes are the sites of protein assembly, Lysosomes digest cellular waste materials, and the Golgi apparatus packages and routes proteins.

Step-by-Step Solution

1
Identify the primary function of Mitochondria.
Mitochondria host cellular respiration to generate ATP, making them the powerhouses of the cell.
This establishes the correct pairing between Mitochondria and Cellular respiration and ATP production.
2
Identify the primary function of Ribosomes.
Ribosomes assemble amino acids into proteins during translation.
This establishes the match between Ribosomes and Protein synthesis.
3
Identify the primary function of Lysosomes.
Lysosomes store digestive enzymes responsible for degrading cellular waste.
This establishes the match between Lysosomes and Intracellular digestion and waste breakdown.
4
Identify the primary function of the Golgi Apparatus.
The Golgi apparatus modifies and packages proteins for transport within or outside the cell.
This establishes the match between Golgi Apparatus and Modification, packaging, and sorting of proteins.

Key Concept

Primary structures and physiological functions of eukaryotic cell organelles
Question 114Question →

In the study of human health and infectious disease epidemiology, precise identification of causative organisms and their biological vectors is critical for effective disease management. Which of the following options correctly matches the infectious disease with its causative microorganism and its primary transmission vector?

Show answer & explanation

Answer: Scrub Typhus �� Orientia tsutsugamushi (Bacterium) — Trombiculid mite

Answer

Scrub Typhus is correctly matched with its causative bacterium Orientia tsutsugamushi and its primary vector, the larval trombiculid mite.
Scrub typhus is an acute infectious zoonotic disease caused by Orientia tsutsugamushi, an obligate intracellular bacterium (formerly classified under Rickettsia). It is transmitted to humans through the bites of infected larval stage trombiculid mites (chiggers), making the disease, pathogen type, and vector combination completely accurate.

Step-by-Step Solution

1
Analyze the pathogen classification for each disease option.
Identify that Orientia tsutsugamushi is a bacterium, Leishmania donovani is a protozoan parasite, Trypanosoma brucei is a protozoan parasite, and Kyasanur Forest Disease agent is a Flavivirus.
Accurate pathogen etiology (bacterial vs viral vs protozoan) is required to eliminate misclassified options.
2
Analyze the transmission vector associated with each disease.
Scrub typhus is transmitted by trombiculid mites, Kala-azar by sandflies, Sleeping sickness by tsetse flies, and KFD by hard ticks (Haemaphysalis spinigera).
Verifying both vector and pathogen components ensures comprehensive matching accuracy.
3
Cross-reference pathogen type and vector for all choices.
Only the pairing of Scrub Typhus with Orientia tsutsugamushi (Bacterium) and Trombiculid mite is entirely correct in both pathogen nature and vector type.
The other options misidentify the biological kingdom/nature of the causative pathogen.

Key Concept

Classification of infectious human diseases by pathogen etiology (bacterial, viral, protozoan) and biological vectors
Estimated Time:1m 30s
Question 115Question →

India's nuclear technology program relies heavily on indigenous research reactors for fissile material production, isotope generation, and technological validation. Arrange the following historical Indian nuclear research reactors in chronological order based on the year of their initial criticality, starting from the earliest to the most recent.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence from earliest to most recent is: Apsara (1956) → CIRUS (1960) → Dhruva (1985) → KAMINI (1996).
The sequence follows the exact historical timeline of initial criticality dates: Apsara was commissioned first in August 1956, followed by CIRUS in July 1960, Dhruva in August 1985, and KAMINI in October 1996.

Step-by-Step Solution

1
Identify the criticality date of Apsara
Apsara achieved criticality on August 4, 1956, making it the earliest research reactor in Asia.
Establishes the starting point of the sequence.
2
Identify the criticality date of CIRUS
CIRUS achieved criticality on July 10, 1960, built with Canadian assistance.
Places CIRUS second in the timeline.
3
Identify the criticality date of Dhruva
Dhruva achieved criticality on August 8, 1985, at the Bhabha Atomic Research Centre (BARC).
Places Dhruva third in the sequence.
4
Identify the criticality date of KAMINI
KAMINI achieved criticality on October 29, 1996, at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam.
Establishes KAMINI as the most recent reactor among the choices.

Key Concept

Chronology of Indian Nuclear Research Reactors
Question 116Question →

Match the bio-fertilizers and beneficial microorganisms listed in List-I with their primary agricultural roles or host associations listed in List-II.

Click a left item, then click its matching right item

Items

Azotobacter
Rhizobium
Anabaena azollae
Mycorrhiza

Matches

Show answer & explanation

Answer

Azotobacter matches with free-living nitrogen-fixing bacterium for non-leguminous crops; Rhizobium matches with symbiotic nitrogen fixer in legume root nodules; Anabaena azollae matches with cyanobacterial symbiont used in rice paddies; and Mycorrhiza matches with fungal association enhancing phosphorus absorption.
Each microorganism corresponds to its primary function in plant nutrition and crop management: Azotobacter fixes nitrogen freely in non-legume soils, Rhizobium forms symbiotic nodules in legumes, Anabaena azollae enriches nitrogen in paddy fields via water fern symbiosis, and Mycorrhiza boosts plant phosphorus absorption.

Step-by-Step Solution

1
Identify the nitrogen-fixing bacteria based on host specificity and habitat.
Rhizobium specifically infects leguminous roots forming nodules, while Azotobacter lives freely in soil around non-legume crops.
Differentiating symbiotic legume fixers from free-living non-legumes is key to matching nitrogen-fixing bacteria.
2
Identify the aquatic bio-fertilizer agent.
Anabaena azollae works symbiotically with Azolla fern in flooded paddy fields to supply bio-available nitrogen.
Azolla-Anabaena system is a classic bio-fertilizer combination for wetland rice agriculture.
3
Identify nutrient absorption fungi.
Mycorrhiza expands root surface area primarily for phosphorus transport.
Mycorrhizae specialize in solubilization and mobilization of immobile soil phosphorus.

Key Concept

Bio-fertilizers and Microorganisms in Sustainable Agriculture
Question 117Question →

Consider the following statements regarding 'Rudram-1', India's indigenously developed missile system:

1. It is India's first indigenous anti-radiation missile, designed to target and destroy enemy radar and communication tracking installations.
2. It uses a liquid-fuel ramjet engine to sustain supersonic propulsion throughout its flight path.
3. It is integrated onto Su-30MKI fighter aircraft and operates using a passive homing head seeker.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

1 and 3 only
Rudram-1 is India's first indigenously developed anti-radiation missile (NGARM), created by DRDO for air-to-surface strikes against enemy radar and communication infrastructure. It is deployed on Su-30MKI fighter jets and guided by a passive homing head. Its propulsion uses a dual-pulse solid rocket motor rather than a liquid-fuel ramjet engine. Therefore, statements 1 and 3 are correct.

Step-by-Step Solution

1
Analyze Statement 1 regarding the operational role of Rudram-1.
Rudram-1 was developed by DRDO as India's premier Next Generation Anti-Radiation Missile (NGARM) to neutralize enemy radio-frequency sources, surveillance radars, and communication sites. Thus, Statement 1 is correct.
Anti-radiation missiles lock onto electromagnetic emissions produced by ground-based enemy radars.
2
Evaluate Statement 2 regarding the propulsion mechanism of Rudram-1.
Rudram-1 is propelled by a dual-pulse solid rocket motor, providing variable thrust during different flight phases rather than using a liquid-fuel ramjet. Thus, Statement 2 is incorrect.
Confusing solid-propellant rocket motors with liquid ramjet engines is a standard distractor in defense technology assessments.
3
Evaluate Statement 3 regarding launch platform integration and guidance systems.
Rudram-1 is integrated into the Indian Air Force's Su-30MKI fighter aircraft and employs a Passive Homing Head (PHH) system to track emissions across a broad band of frequencies. Thus, Statement 3 is correct.
Passive homing head sensors allow the missile to detect and track target signals without revealing its own presence.

Key Concept

Rudram-1 Anti-Radiation Missile and Solid-Propellant Propulsion
Estimated Time:1m 30s
Question 118Question →

Match the human hormonal deficiency conditions listed in List-I with their corresponding causative hormonal imbalances in List-II:

Click a left item, then click its matching right item

Items

Diabetes Insipidus
Addison's Disease
Cretinism
Diabetes Mellitus

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Answer

Diabetes Insipidus corresponds to Hyposecretion of Vasopressin; Addison's Disease corresponds to Hyposecretion of Glucocorticoids; Cretinism corresponds to Congenital deficiency of Thyroid Hormone; Diabetes Mellitus corresponds to Hyposecretion or impaired action of Insulin.
Each pathological condition directly matches its underlying endocrine gland defect: Diabetes Insipidus is caused by vasopressin deficiency, Addison's disease by adrenocortical steroid (cortisol) deficiency, Cretinism by infantile hypothyroidism, and Diabetes Mellitus by pancreatic insulin deficiency.

Step-by-Step Solution

1
Identify the etiology of Diabetes Insipidus
Vasopressin (ADH) controls water retention in kidney tubules. Its deficiency causes Diabetes Insipidus.
Deficiency of ADH prevents reabsorption of water, causing polyuria and polydipsia without glucose elevation.
2
Identify the etiology of Addison's Disease
Destruction or autoimmune impairment of the adrenal cortex causes deficiency of Cortisol, leading to Addison's disease.
The adrenal cortex produces glucocorticoids essential for electrolyte balance and stress response.
3
Identify the etiology of Cretinism
Thyroid hormone deficiency during embryonic development or early infancy causes Cretinism.
Thyroxine is vital for central nervous system maturation and skeletal growth.
4
Identify the etiology of Diabetes Mellitus
Deficiency in secretion or activity of pancreatic Insulin causes Diabetes Mellitus.
Insulin facilitates cellular uptake of glucose; its absence leads to systemic hyperglycemia.

Key Concept

Human Endocrine Physiology and Hormonal Deficiency Pathology
Question 119Question →

Regarding the technological specifications, moderator requirements, and fuel cycles of nuclear power reactors developed under India's nuclear energy roadmap, which of the following statements are correct?

Select all that apply

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Answer: Pressurised Heavy Water Reactors (PHWRs) utilize natural uranium as fuel and heavy water (D2OD_2O) as both coolant and moderator.; Fast Breeder Reactors (FBRs) utilize liquid sodium as a coolant and operate without a neutron moderator to sustain fast neutron fission.; The Kamini research reactor at Kalpakkam is notable for using Uranium-233 fuel bred from thorium irradiation.

Answer

The statements stating that PHWRs use natural uranium with heavy water as moderator/coolant, FBRs use liquid sodium without a moderator, and the Kamini reactor uses Uranium-233 fuel are all correct.
Pressurised Heavy Water Reactors efficiently maintain criticality using natural uranium because heavy water minimizes neutron capture. Fast Breeder Reactors require fast neutrons to breed fissile plutonium, which necessitates a non-moderating coolant like liquid sodium. Kamini is a pioneering reactor running on Uranium-233 fuel.

Step-by-Step Solution

1
Evaluate the moderator and fuel requirements of Pressurised Heavy Water Reactors (PHWRs).
PHWRs use natural uranium containing 0.7%0.7\% U-235. Heavy water (D2OD_2O) slows down neutrons without capturing them excessively, making fuel enrichment unnecessary.
Heavy water has a very low neutron capture cross-section compared to light water.
2
Analyze the operational physics of Fast Breeder Reactors (FBRs).
FBRs require fast neutrons to transmute fertile U-238 into fissile Pu-239. Liquid sodium is used as coolant because it efficiently removes heat without moderating neutron speed.
Adding a moderator would thermalize neutrons, preventing fast-neutron breeding reaction cycles.
3
Examine the fuel characteristics of the Kamini research reactor.
Kamini uses U-233 fuel generated from India's thorium reserves, marking a key milestone in Stage-3 technology development.
It serves as a neutron radiography facility demonstrating the utilization of the Thorium fuel cycle.

Key Concept

Nuclear reactor physics, coolant/moderator selection, and stage-wise fuel cycles in nuclear power programs.
Question 120Question →

Consider the following statements regarding India's nuclear technology and three-stage nuclear power programme:

1. Pressurised Heavy Water Reactors (PHWRs), which form the backbone of Stage-1 of the programme, utilize natural uranium as fuel and heavy water (D2OD_2O) as both neutron moderator and coolant.
2. The Prototype Fast Breeder Reactor (PFBR) at Kalpakkam (Stage-2) operates using fast neutrons without a neutron moderator, employing liquid sodium as the heat transfer coolant.
3. In Stage-3 of the nuclear energy roadmap, Thorium-232 is designed to be used directly as a primary fissile fuel without requiring prior nuclear transmutation into Uranium-233.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 2 only

Answer

1 and 2 only
The correct response is the option stating '1 and 2 only'. Stage-1 PHWRs use natural uranium fueled with heavy water (D2OD_2O) as both coolant and moderator. Stage-2 Fast Breeder Reactors operate without a moderator to maintain fast neutron flux for breeding Plutonium-239, using liquid sodium as the heat exchange medium. Statement 3 is false because Thorium-232 is fertile and cannot undergo direct nuclear fission without prior transmutation into Uranium-233.

Step-by-Step Solution

1
Evaluate Statement 1 regarding Stage-1 Pressurised Heavy Water Reactors (PHWRs).
Statement 1 is correct. PHWRs utilize unenriched natural uranium (≈0.7% U-235\approx 0.7\% \text{ U-235}) as fuel. Heavy water (D2OD_2O) serves as both moderator and coolant due to its extremely low neutron absorption cross-section.
Low neutron absorption by heavy water allows critical chain reactions to be sustained with natural uranium fuel.
2
Evaluate Statement 2 regarding Stage-2 Fast Breeder Reactor technology.
Statement 2 is correct. Fast Breeder Reactors like the PFBR at Kalpakkam do not use a moderator because high-energy (fast) neutrons are essential to convert fertile Uranium-238 into fissile Plutonium-239. Liquid sodium is used as a coolant because of its excellent thermal conductivity and low moderation properties.
Moderators slow down neutrons, which would prevent the fast-neutron breeding ratio from exceeding unity.
3
Evaluate Statement 3 regarding Stage-3 Thorium utilization.
Statement 3 is incorrect. Thorium-232 is a fertile isotope, not a fissile isotope. It cannot sustain a fission chain reaction on its own and must absorb a neutron to undergo nuclear transmutation (via Beta decay) into fissile Uranium-233 (232Th+n→233Th→β−233Pa→β−233U^{232}\text{Th} + n \rightarrow ^{233}\text{Th} \xrightarrow{\beta^-} ^{233}\text{Pa} \xrightarrow{\beta^-} ^{233}\text{U}).
Fertile materials cannot serve directly as primary fissile fuel without prior conversion.
4
Select the correct combination of true statements.
Statements 1 and 2 are true, making the combination '1 and 2 only' the correct choice.
Only statement 3 contains a conceptual error in nuclear physics.

Key Concept

India's Three-Stage Nuclear Power Programme (PHWR vs FBR vs Thorium Fuel Cycle)
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