Examkin

General Science and Technology

222 questions

All types222Multiple choice117Multiple select40True / False8Matching44Ordering13
Question 21Question →

Malaria remains a major public health concern in many tropical and subtropical regions. Which of the following microorganisms is the actual causative pathogen responsible for malaria in humans?

Show answer & explanation

Answer: Plasmodium parasite

Answer

The causative pathogen responsible for malaria in humans is the Plasmodium parasite.
The Plasmodium parasite is the single-celled protozoan that invades human erythrocytes and liver cells, causing malaria.

Step-by-Step Solution

1
Distinguish between a disease pathogen (the organism causing illness) and a vector (the organism transporting the pathogen).
Plasmodium is identified as the microscopic pathogen, while mosquitoes serve as vectors.
Medical parasitology categorizes infectious diseases by their etiological microbe.
2
Identify the specific microorganism causing malaria.
Plasmodium species (such as P. falciparum and P. vivax) are protozoan parasites responsible for malarial infection.
Female Anopheles mosquitoes only inject Plasmodium sporozoites into the host during a blood meal.

Key Concept

Distinction between infectious pathogens and disease vectors in human health
Question 22Question →

Which of the following statements regarding everyday optical phenomena and their underlying physical principles are correct?

Select all that apply

Show answer & explanation

Answer: The formation of a secondary rainbow involves two internal reflections and two refractions of sunlight within raindrops, causing its color sequence to be reversed relative to a primary rainbow.; Sun dogs (parhelia) and 22∘22^\circ atmospheric halos are produced primarily by the refraction of sunlight passing through hexagonal ice crystals suspended in high-altitude cirrus clouds.

Answer

The correct statements are the statement explaining secondary rainbow formation through two internal reflections and refractions with reversed spectral order, and the statement describing sun dogs and halos as the refraction of light through hexagonal ice crystals.
The statements describing secondary rainbow optics and atmospheric ice halos are physically accurate. A secondary rainbow forms after two internal reflections and two refractions inside water droplets, reversing the color order (red inside, violet outside). Sun dogs and 22∘22^\circ atmospheric halos occur when sunlight refracts through hexagonal ice crystals suspended in cirrus clouds at the angle of minimum deviation.

Step-by-Step Solution

1
Analyze rainbow optics mechanics
Primary rainbows involve 1 internal reflection and 2 refractions. Secondary rainbows involve 2 internal reflections and 2 refractions, which reverses the angular dispersion order of light colors.
Verifies the statement regarding secondary rainbow optics as true.
2
Evaluate atmospheric scattering wavelength dependence
Rayleigh scattering intensity follows I∝1λ4I \propto \frac{1}{\lambda^4}. The statement incorrectly asserts a inverse-square relationship (1/λ21/\lambda^2).
Identifies the atmospheric scattering statement as incorrect due to an incorrect power exponent.
3
Examine ice crystal optical phenomena (halos and sun dogs)
Hexagonal ice crystals act as 60∘60^\circ prisms causing light refraction at a minimum deviation angle of 22∘22^\circ, producing 22∘22^\circ halos and parhelia (sun dogs).
Confirms the sun dog and halo mechanism statement as true.
4
Check conditions for Total Internal Reflection (TIR) in fiber optics
TIR requires light to propagate from a higher refractive index medium to a lower refractive index medium (ncore>ncladdingn_{\text{core}} > n_{\text{cladding}}). The statement claims ncore<ncladdingn_{\text{core}} < n_{\text{cladding}}, which is false.
Determines the optical fiber parameter statement to be false.

Key Concept

Everyday Wave Optics and Atmospheric Optical Phenomena
Question 23Question →

Rear-view mirrors fitted on the sides of automobiles assist drivers by enabling them to see traffic coming from behind. Which type of mirror is primarily used for this purpose, and why?

Show answer & explanation

Answer: Convex mirror, because it forms an erect and diminished image, offering a wider field of view

Answer

Convex mirrors are used as rear-view mirrors in vehicles because they form erect, virtual, and diminished images, providing the driver with a significantly wider field of view.
Convex mirrors curve outward, causing reflected rays of light to spread apart (diverge). This curvature allows them to form erect, virtual, and diminished images for objects at any distance, giving the driver a significantly wider field of view compared to flat or concave mirrors.

Step-by-Step Solution

1
Determine the necessary visual features of a vehicle rear-view mirror
The driver requires an upright (erect) view of approaching vehicles that covers a broad physical area.
An inverted image would confuse the driver, and a narrow view would leave dangerous blind spots.
2
Analyze image formation across different mirror types
A convex mirror diverges reflected rays and consistently produces an erect and diminished image regardless of object distance.
Because the images formed are smaller than the actual objects, a larger scene fits into the mirror surface, maximizing the field of view.

Key Concept

Everyday applications of curved mirrors and image formation by convex mirrors
Question 24Question →

Which of the following statements regarding human infectious diseases and their causative pathogens are correct?

Select all that apply

Show answer & explanation

Answer: Tuberculosis is caused by a bacterial pathogen that primarily affects the respiratory system.; Dengue fever is a viral infection transmitted to humans through the bite of infected Aedes mosquitoes.

Answer

The statements identifying Tuberculosis as a bacterial disease and Dengue as a viral vector-borne disease are correct.
Tuberculosis is accurately identified as a bacterial disease caused by Mycobacterium tuberculosis, and Dengue fever is correctly identified as a viral disease transmitted by Aedes mosquitoes.

Step-by-Step Solution

1
Analyze the statement regarding Tuberculosis
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, which typically attacks the lungs. Thus, this statement is correct.
Correct classification of the pathogen as bacterial.
2
Analyze the statement regarding Dengue fever
Dengue is a arboviral infection transmitted by Aedes aegypti mosquitoes. Thus, this statement is correct.
Correct classification of Dengue as viral and its vector as Aedes.
3
Analyze the statements regarding Cholera and Typhoid
Cholera is caused by the bacterium Vibrio cholerae (not a protozoan), and Typhoid is caused by the bacterium Salmonella Typhi (transmitted food/water-borne, not air-borne). Both statements are incorrect.
Identification of pathogen and transmission misclassifications.

Key Concept

Classification of Human Infectious Diseases by Pathogen Type (Bacterial vs. Viral vs. Protozoan)
Question 25Question →

Match the everyday physical phenomena and devices in List-I with their underlying physics principles in List-II, and select the correct matching pairs:

Click a left item, then click its matching right item

Items

Transmission of light signals through flexible optical fibers in telecommunications
Cooling of stored water inside a porous earthenware pitcher during hot weather
Production of vibrant iridescent color patterns on thin oil films floating on water
Detection of underwater obstacles and seafloor depth mapping using SONAR systems

Matches

Show answer & explanation

Answer

The correct pairings link: optical fiber transmission with total internal reflection; earthenware pitcher cooling with latent heat absorption during surface evaporation; thin oil film colors with thin-film optical wave interference; and SONAR underwater mapping with acoustic wave reflection.
Each phenomenon is matched strictly to its core physics principle: total internal reflection keeps light confined inside telecommunication fibers; evaporative cooling extracts latent heat to lower water temperature in porous vessels; thin-film wave interference produces iridescence on oil slicks; and acoustic wave reflection enables distance calculations in SONAR navigation.

Step-by-Step Solution

1
Analyze the principle behind optical fiber data transmission.
Optical fibers require light signals to stay contained inside the glass core without escaping, which is achieved by total internal reflection at the core-cladding interface.
Light striking the boundary at an angle greater than the critical angle undergoes complete reflection back into the denser core.
2
Examine the thermodynamics of water cooling in an earthenware pitcher.
Water seeps through pores to the exterior where it undergoes phase change into vapor, absorbing latent heat of vaporization from the body of water.
Evaporation is a cooling process because escaping high-energy molecules reduce the mean kinetic energy of the remaining liquid.
3
Investigate the optical mechanism responsible for colorful oil slicks.
Light reflected from the upper surface of the oil film combines with light reflected from the lower oil-water interface, undergoing thin-film interference.
Depending on film thickness and wavelength, specific colors experience constructive interference while others undergo destructive interference.
4
Identify the acoustic mechanism utilized in SONAR systems.
SONAR devices emit ultrasonic pulses and detect reflected echoes returning from submerged surfaces.
Knowing the speed of sound in seawater and measuring echo return time yields precise distance measurements via wave reflection principles.

Key Concept

Everyday Applications of Wave Optics, Acoustic Reflection, and Thermal Phase Transitions
Question 26Question →

With reference to infectious human diseases and their causative microorganisms, consider the following pairs:

1. Kala-azar — Protozoa
2. Dengue — Bacterium
3. African Sleeping Sickness �� Virus
4. Tuberculosis — Bacterium

Which of the pairs given above are correctly matched?

Show answer & explanation

Answer: 1 and 4 only

Answer

1 and 4 only
Pairs 1 and 4 are accurate. Kala-azar is a protozoan disease caused by Leishmania donovani, while Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis. Dengue is caused by a virus and Sleeping Sickness is caused by a protozoan parasite, making pairs 2 and 3 incorrect.

Step-by-Step Solution

1
Analyze pair 1 (Kala-azar — Protozoa)
Correctly matched
Kala-azar (Visceral Leishmaniasis) is caused by protozoan parasites of the species Leishmania donovani transmitted by sandflies.
2
Analyze pair 2 (Dengue — Bacterium)
Incorrectly matched
Dengue is a viral infection caused by the Dengue virus (DENV) transmitted by Aedes mosquitoes.
3
Analyze pair 3 (African Sleeping Sickness — Virus)
Incorrectly matched
African Sleeping Sickness (Human African Trypanosomiasis) is caused by microscopic protozoan parasites of the species Trypanosoma brucei.
4
Analyze pair 4 (Tuberculosis — Bacterium)
Correctly matched
Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis.

Key Concept

Classification of Human Infectious Diseases by Causative Pathogen Types
Question 27Question →

Match the everyday physical phenomena listed under List-I with their corresponding underlying physics principles listed under List-II:

Click a left item, then click its matching right item

Items

Spherical shape of small falling raindrops
Transmission of light signals through optical fibers
Change in pitch of a siren as an ambulance passes by
Operation of hydraulic braking systems in automobiles

Matches

Show answer & explanation

Answer

Spherical shape of falling raindrops matches with Surface tension; Transmission of light signals through optical fibers matches with Total internal reflection; Change in pitch of a siren matches with Doppler effect; Operation of hydraulic braking systems matches with Pascal's law.
Each listed phenomenon directly pairs with its underlying fundamental physical principle: drop curvature relates to surface tension, fiber optic signal propagation relies on total internal reflection, siren pitch variations depend on the Doppler effect, and hydraulic force transmission relies on Pascal's law.

Step-by-Step Solution

1
Identify the physical principle behind the spherical shape of raindrops.
Unbalanced cohesive forces at the liquid-air interface create surface tension, causing drops to pull into minimum surface area (spherical shape).
This links fluid surface dynamics with droplet geometry.
2
Identify the physical principle governing signal transmission in optical fibers.
Light entering the core at an angle greater than the critical angle undergoes repeated total internal reflection with minimal loss.
This links light propagation inside bounded media with wave optics.
3
Identify the acoustic phenomenon caused by moving sound sources like sirens.
Relative motion compresses or expands wave fronts, altering perceived pitch via the Doppler effect.
This links wave kinematics with frequency perception.
4
Identify the mechanical principle utilized in hydraulic vehicle brakes.
Fluid pressure applied at a master cylinder is transmitted uniformly throughout fluid lines to wheel cylinders following Pascal's law.
This links force amplification in enclosed fluids with fluid mechanics.

Key Concept

Everyday applications of fundamental physics principles across fluid mechanics, optics, and wave acoustics.
Question 28Question →

Match the blood cell types listed in List-I with their primary physiological functions listed in List-II:

Click a left item, then click its matching right item

Items

Neutrophils
Eosinophils
Basophils
Plasma Cells

Matches

Show answer & explanation

Answer

Neutrophils pair with rapid phagocytosis of bacterial pathogens; Eosinophils pair with defense against multicellular parasites and modulation of allergic responses; Basophils pair with release of histamine and heparin during inflammatory reactions; Plasma cells pair with secretion of specific antibodies for humoral immunity.
Each leukocyte type possesses distinct morphological features and physiological responsibilities: Neutrophils act primarily as rapid bacterial phagocytes, Eosinophils combat parasitic infections and modulate allergic mediators, Basophils secrete histamine and heparin during inflammatory cascades, and Plasma cells produce circulating antibodies responsible for adaptive humoral immunity.

Step-by-Step Solution

1
Analyze the physiological function of Neutrophils.
Neutrophils are granulocytes specialized in acute bacterial phagocytosis.
They are the most abundant white blood cells and arrive first at infection sites.
2
Analyze the functional role of Eosinophils.
Eosinophils target parasitic organisms and regulate histamine levels.
Their granules contain major basic protein and histaminase targeting helminths and allergic reactions.
3
Analyze the functional role of Basophils.
Basophils mediate inflammatory responses through histamine and heparin release.
They share functional similarities with tissue mast cells in hypersensitivity pathways.
4
Analyze the functional role of Plasma Cells.
Plasma cells secrete immunoglobulins (antibodies).
They derive from activated B lymphocytes and drive humoral adaptive immunity.

Key Concept

Leukocyte Functional Specialization in Human Immune Physiology
Question 29Question →

When a thin film of oil spreads over water on a road surface, vibrant multi-colored patterns are observed under sunlight. A candidate preparing for a competitive examination confuses this optical effect with the mechanism that causes the clear sky to appear blue. Which of the following statements correctly identifies the physical principle responsible for the oil film's colorful appearance and distinguishes it from the blue sky phenomenon?

Show answer & explanation

Answer: The colorful patterns on the oil film are caused by thin-film wave interference between light reflected from the upper and lower boundaries of the oil layer, whereas the blue sky is caused by Rayleigh scattering of sunlight by atmospheric gas molecules.

Answer

The colorful patterns on the oil film are caused by thin-film wave interference between light reflected from the upper and lower boundaries of the oil layer, whereas the blue sky is caused by Rayleigh scattering of sunlight by atmospheric gas molecules.
The correct response correctly identifies that light reflecting from both the upper (air-oil) and lower (oil-water) boundaries of a thin oil film undergoes wave interference, producing colorful spectral fringes. In contrast, the blue sky is caused by Rayleigh scattering, where air molecules selectively scatter shorter blue wavelengths of sunlight in all directions.

Step-by-Step Solution

1
Analyze the optical mechanism of thin oil films on water
Sunlight strikes the top surface of the thin oil film. Part of the light reflects off the top boundary (air-oil interface), while the rest transmits through the film and reflects off the bottom boundary (oil-water interface).
When these two reflected light waves recombine, they undergo constructive or destructive interference depending on the film thickness and wavelength of light, creating rainbow-like interference patterns.
2
Analyze the optical mechanism responsible for the blue appearance of the daytime sky
Sunlight entering Earth's atmosphere collides with air molecules (N2,O2N_2, O_2) whose sizes are much smaller than the wavelength of visible light.
According to Rayleigh scattering law, scattered intensity I∝1λ4I \propto \frac{1}{\lambda^4}. Shorter blue wavelengths scatter much more efficiently than longer red wavelengths, filling the sky with diffuse blue light.
3
Compare the two phenomena to select the correct choice
Oil film colors stem from wave superposition (thin-film interference), whereas sky color stems from elastic scattering by small particles (Rayleigh scattering).
Differentiating superposition phenomena from scattering processes eliminates all distractor options.

Key Concept

Thin-Film Interference vs. Rayleigh Scattering
Estimated Time:1m 30s
Question 30Question →

Kala-azar (Visceral Leishmaniasis) is a major public health concern in several regions of India. Which type of microorganism is the primary causative pathogen of Kala-azar?

Show answer & explanation

Answer: Protozoan

Answer

Protozoan parasite (Leishmania donovani)
Kala-azar (Visceral Leishmaniasis) is caused by the protozoan parasite *Leishmania donovani*, which is transmitted to humans through the bites of infected female phlebotomine sandflies.

Step-by-Step Solution

1
Identify the disease and its biological agent.
Kala-azar (Visceral Leishmaniasis) is caused by the parasite *Leishmania donovani*.
Understanding the pathogen classification helps distinguish protozoal diseases from bacterial or viral infections.
2
Classify the biological parasite category.
*Leishmania donovani* is a single-celled eukaryotic parasite belonging to the phylum Protozoa.
Categorizing microorganisms accurately is fundamental in human health and disease taxonomy.

Key Concept

Infectious Disease Pathogen Classification
Question 31Question →

During a quiet night, distant sounds such as train whistles or acoustic announcements are often heard much more clearly and over greater distances than during a hot afternoon. Which of the following physical phenomena primarily accounts for this atmospheric acoustic effect?

Show answer & explanation

Answer: Refraction of sound waves caused by a vertical temperature gradient in the lower atmosphere

Answer

Refraction of sound waves caused by a vertical temperature gradient in the lower atmosphere
The correct answer highlights atmospheric refraction resulting from a temperature inversion. At night, the surface air cools rapidly while higher air layers remain warmer. Because sound speed increases with air temperature, the upper portion of a sound wave front travels faster than its base. This causes sound rays heading upward to curve back down toward the ground, allowing sound to cover significantly greater distances with higher intensity.

Step-by-Step Solution

1
Analyze atmospheric conditions during nighttime versus daytime.
During the day, ground heating creates warmer air near the surface and cooler air above. At night, radiational cooling of the Earth makes the ground air colder than the air layer above it (temperature inversion).
Temperature distribution dictates the local speed of sound in air.
2
Relate temperature to the speed of sound.
The speed of sound in air is proportional to the square root of absolute temperature (v∝Tv \propto \sqrt{T}). Consequently, sound travels faster through warmer air layers than through colder air layers.
Wave fronts bend toward regions of lower wave speed according to Snell's law of refraction.
3
Determine the path of wave propagation at night.
As upward-moving sound wave fronts encounter warmer air higher up, the top part of the wave front moves faster than the bottom part. This differential speed bends (refracts) the acoustic wave path back downward toward the Earth's surface.
Downward refraction traps and redirects sound energy along the ground rather than letting it dissipate upward into the atmosphere.

Key Concept

Atmospheric Refraction of Sound Waves
Estimated Time:2m 0s
Question 32Question →

Consider the following statements regarding vector-borne human diseases:

1. Kala-azar (Visceral Leishmaniasis) is caused by a protozoan parasite and is transmitted to humans through the bite of infected female sandflies.
2. Lymphatic Filariasis (Elephantiasis) is a viral disease primarily transmitted by the bite of Aedes mosquitoes.
3. Japanese Encephalitis is an acute bacterial infection transmitted to humans by Culex mosquitoes.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 only

Answer

1 only
The option stating '1 only' is correct because statement 1 accurately identifies Kala-azar as a protozoan disease transmitted by sandflies. Statement 2 incorrectly terms Lymphatic Filariasis a viral infection (it is caused by parasitic filarial worms), and statement 3 incorrectly terms Japanese Encephalitis a bacterial infection (it is caused by a virus).

Step-by-Step Solution

1
Evaluate Statement 1 regarding Kala-azar
Statement 1 is correct.
Kala-azar (Visceral Leishmaniasis) is caused by the protozoan parasite Leishmania donovani and is transmitted through the bite of infected female Phlebotomine sandflies.
2
Evaluate Statement 2 regarding Lymphatic Filariasis
Statement 2 is incorrect.
Lymphatic Filariasis is caused by microscopic filarial nematode worms (helminths such as Wuchereria bancrofti), not viruses. It is primarily transmitted by mosquitoes of the genus Culex.
3
Evaluate Statement 3 regarding Japanese Encephalitis
Statement 3 is incorrect.
Japanese Encephalitis is caused by the Japanese Encephalitis Virus (JEV), a flavivirus, rather than a bacterial pathogen, although it is indeed transmitted by Culex mosquitoes.

Key Concept

Etiology and Vector Differentiation of Infectious Human Diseases
Estimated Time:1m 30s
Question 33Question →

Match the everyday physical observations in List-I with their underlying physics principles in List-II:

Click a left item, then click its matching right item

Items

Spherical shape of small falling raindrops
Operation of hydraulic brakes in automobiles
Apparent twinkling of stars in the night sky
Cooling effect of water stored in an earthen pot (matka)

Matches

Show answer & explanation

Answer

The correct matching pairs are: Spherical shape of falling raindrops matches with Minimization of surface area driven by Surface Tension; Operation of hydraulic brakes matches with Equal transmission of fluid pressure according to Pascal's Law; Apparent twinkling of stars matches with Light ray deviation caused by Atmospheric Refraction; and Cooling effect of water in an earthen pot matches with Latent heat absorption during Evaporative Cooling.
Each observation directly matches its underlying physical law: surface tension minimizes surface area for raindrops; Pascal's Law governs hydraulic pressure transmission; atmospheric refraction causes stellar twinkling; and latent heat absorption during evaporation cools water in porous vessels.

Step-by-Step Solution

1
Identify the cause behind the spherical geometry of small falling liquid drops.
Cohesive intermolecular forces at the liquid surface create surface tension, minimizing the surface area into a sphere.
A sphere possesses the smallest surface-area-to-volume ratio among all geometric shapes.
2
Analyze the operational principle of hydraulic braking systems.
Force applied to the brake pedal creates pressure in the brake fluid, which is transmitted equally across the system to actuate pistons at the wheels.
According to Pascal's Law, static fluid pressure is transmitted undiminished throughout an enclosed fluid system.
3
Determine the cause of stellar scintillation (twinkling).
Starlight passes through turbulent atmospheric layers with fluctuating temperatures and optical densities, causing constant shifting of the ray paths.
Atmospheric refraction alters the apparent brightness and position of point-source light continuously.
4
Explain the thermodynamic cooling of water in porous earthen vessels.
Water seeping out through microscopic pores evaporates from the outer surface, extracting thermal energy from the pot.
Evaporation requires energy equivalent to the latent heat of vaporization, lowering the temperature of the remaining system.

Key Concept

Everyday Applications of Surface Tension, Fluid Pressure, Atmospheric Refraction, and Evaporative Cooling
Question 34Question →

Consider the following statements regarding certain human infectious diseases and their causative organisms:

1. Japanese Encephalitis is a viral infection transmitted to humans predominantly by vector mosquitoes belonging to the genus *Culex*.
2. Typhoid fever is a acute viral infection caused by the pathogen *Salmonella typhi*.
3. Lymphatic Filariasis is caused by parasitic filarial worms transmitted through mosquito bites.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

1 and 3 only
The correct combination includes statements 1 and 3. Japanese Encephalitis is a viral encephalitic disease transmitted by *Culex* mosquitoes, and Lymphatic Filariasis is a parasitic worm infection transmitted by vector mosquitoes. Statement 2 is false because Typhoid fever is a bacterial disease caused by *Salmonella typhi*.

Step-by-Step Solution

1
Evaluate Statement 1 regarding Japanese Encephalitis
Statement 1 is correct. Japanese Encephalitis is caused by the Japanese encephalitis virus (JEV), a flavivirus, and is transmitted to humans by bites from infected mosquitoes, primarily *Culex tritaeniorhynchus*.
Verify the pathogen category (virus) and vector group (*Culex* mosquito).
2
Evaluate Statement 2 regarding Typhoid fever
Statement 2 is incorrect. Typhoid fever is caused by the bacterium *Salmonella enterica* serovar Typhi (*Salmonella typhi*), not a virus.
Identify the biological nature of the causative microorganism (bacterium vs virus).
3
Evaluate Statement 3 regarding Lymphatic Filariasis
Statement 3 is correct. Lymphatic Filariasis (commonly known as elephantiasis) is caused by microscopic, thread-like parasitic nematodes (such as *Wuchereria bancrofti*) transmitted by mosquitoes.
Verify the etiology of filariasis as a parasitic helminthic disease spread via mosquito vectors.

Key Concept

Etiology and Vector Transmission of Infectious Human Diseases
Estimated Time:1m 0s
Question 35Question →

Which national agency is designated under Section 70B of the Information Technology Act, 2000 to serve as the national nodal agency for performing cybersecurity incident response functions in India?

Show answer & explanation

Answer: Indian Computer Emergency Response Team (CERT-In)

Answer

Indian Computer Emergency Response Team (CERT-In)
Section 70B of the Information Technology Act, 2000 designates the Indian Computer Emergency Response Team (CERT-In) under the Ministry of Electronics and Information Technology as the national nodal agency for cybersecurity functions such as incident response, vulnerability reporting, and cyber threat alerts.

Step-by-Step Solution

1
Identify the specific legal provision mentioned in the question.
The question refers to Section 70B of the Information Technology Act, 2000.
Section 70B explicitly outlines the statutory mandate for cyber incident handling in India.
2
Recall the designated statutory body appointed under Section 70B.
The Indian Computer Emergency Response Team (CERT-In) is designated as the national nodal agency.
CERT-In is tasked with collecting, analyzing, and disseminating information on cyber incidents.

Key Concept

Statutory Nodal Agency for Cybersecurity under IT Act 2000
Question 36Question →

Epidemiological surveillance relies on precisely categorizing pathogen types and their transmission vectors. Which of the following statements correctly describe the etiology and transmission dynamics of human infectious diseases?

Select all that apply

Show answer & explanation

Answer: Bubonic plague is a bacterial infection caused by Yersinia pestis, primarily transmitted to humans through the bites of infected oriental rat fleas (Xenopsylla cheopis).; Epidemic typhus is caused by the bacterium Rickettsia prowazekii and is vector-transmitted to humans by the human body louse (Pediculus humanus humanus).

Answer

The correct statements are the ones describing Bubonic plague as a bacterial infection transmitted by rat fleas, and Epidemic typhus as a bacterial infection caused by Rickettsia prowazekii transmitted by the human body louse.
The statements describing Bubonic plague and Epidemic typhus are scientifically accurate. Bubonic plague is caused by the Gram-negative bacterium Yersinia pestis and spread by the rat flea Xenopsylla cheopis. Epidemic typhus is caused by the obligate intracellular bacterium Rickettsia prowazekii, transmitted by the human body louse Pediculus humanus humanus.

Step-by-Step Solution

1
Evaluate the statement regarding Bubonic plague.
Bubonic plague is correctly identified as a bacterial disease caused by Yersinia pestis and vector-transmitted by rat fleas (Xenopsylla cheopis).
This aligns with pathogen and vector taxonomy.
2
Evaluate the statement regarding Brucellosis.
Brucellosis is incorrectly classified as a mosquito-borne protozoan disease.
Brucellosis is a bacterial infection (Brucella spp.) spread via raw dairy products or exposure to fluids of infected livestock.
3
Evaluate the statement regarding Epidemic typhus.
Epidemic typhus is correctly identified as a rickettsial bacterial infection transmitted by the body louse.
Rickettsia prowazekii is transmitted when louse feces are rubbed into vector bite wounds or mucous membranes.
4
Evaluate the statement regarding Malaria.
Malaria is incorrectly described as a waterborne bacterial lymphatic infection.
Malaria is caused by protozoans (Plasmodium falciparum, P. vivax, etc.) transmitted vectorially by female Anopheles mosquitoes.

Key Concept

Classification of human infectious diseases by pathogen domain (bacterium vs. protozoan) and primary transmission vectors.
Estimated Time:2m 0s
Question 37Question →

In symmetric key cryptography, the sender and the recipient use two distinct keys—a public key for encrypting data and a private key for decrypting data.

Show answer & explanation

Answer: False

Answer

The statement is False. Symmetric key cryptography relies on a single shared secret key for both encryption and decryption, whereas asymmetric key cryptography uses a public-private key pair.
The statement is false because symmetric key encryption algorithms (such as AES or DES) employ a single secret key shared between the sender and receiver for both encryption and decryption. A public and private key pair is used exclusively in asymmetric key cryptography (such as RSA or ECC).

Step-by-Step Solution

1
Analyze the core definition of symmetric key cryptography.
Symmetric key cryptography uses the exact same key to both encrypt and decrypt information.
Establishing foundational cryptographic terminology.
2
Compare the statement's description with cryptographic definitions.
The statement describes public-key (asymmetric) cryptography, not symmetric key cryptography.
Differentiating symmetric encryption from asymmetric key pair mechanisms.

Key Concept

Symmetric vs. Asymmetric Cryptography Key Architecture
Estimated Time:45s
Question 38Question →

Which of the following statements regarding fundamental cryptographic principles and cybersecurity architectures are correct?

Select all that apply

Show answer & explanation

Answer: Cryptographic hash functions are deterministic, one-way algorithms that produce a fixed-length output digest regardless of the input data size.; Zero Trust Network Architecture operates on the core principle of 'never trust, always verify', enforcing continuous identity authentication regardless of user location.

Answer

The correct statements are those identifying hash functions as deterministic one-way algorithms producing fixed-length digests, and defining Zero Trust Network Architecture as requiring continuous authentication under the 'never trust, always verify' paradigm.
Cryptographic hash functions always process arbitrary input lengths to generate a uniform fixed-size digest that cannot be mathematically reversed. Furthermore, modern Zero Trust Architecture strictly eliminates implicit network trust, demanding continuous identity authentication and explicit access authorization for all requests.

Step-by-Step Solution

1
Evaluate the statement regarding cryptographic hash functions.
Confirmed correct. Hash algorithms (e.g., SHA-256) generate fixed-size outputs (digests) from inputs of any length and are mathematical one-way functions.
Hashing is fundamental for data integrity verification in digital signatures and password storage.
2
Analyze the statement describing symmetric-key cryptography.
Identified as incorrect. Symmetric encryption relies on a single shared key for both operations, whereas key pairs (public/private) define asymmetric cryptography.
Confusing symmetric and asymmetric key structures is a common conceptual misconception.
3
Assess the statement describing Zero Trust Network Architecture.
Confirmed correct. Zero Trust mandates strict identity verification and least-privilege access controls regardless of whether an device is inside or outside the corporate network perimeter.
Zero Trust shifts security enforcement from legacy network boundaries to granular user and device identity checks.
4
Examine the statement defining a Denial of Service attack.
Identified as incorrect. Encrypting data for ransom defines Ransomware, whereas DoS attacks aim to exhaust bandwidth or system resources to render services unavailable.
Differentiating cyber attack vectors is vital for understanding threat mechanisms.

Key Concept

Cryptographic Foundations, Key Exchange Models, Zero Trust Security, and Threat Classifications
Question 39Question →

Which plant hormone is primarily synthesized in response to water stress to induce stomatal closure and minimize transpiration loss?

Show answer & explanation

Answer: Abscisic acid

Answer

Abscisic acid is the primary plant hormone responsible for inducing stomatal closure during water stress conditions.
Abscisic acid serves as a plant stress signaling hormone. When plants experience drought, roots and leaves synthesize abscisic acid, which travels to leaf guard cells and prompts them to close stomata, thereby conserving water.

Step-by-Step Solution

1
Identify the stress condition described in the stem
Water stress (drought) causing excessive moisture loss through transpiration.
Plants need a rapid hormonal signal to conserve water when soil moisture decreases.
2
Determine the specific plant growth regulator involved
Abscisic acid acts as the principal stress hormone.
Increased levels of abscisic acid trigger an efflux of potassium ions from guard cells, leading to water loss from guard cells and closure of the stomatal pore.

Key Concept

Plant Hormones and Stress Physiology
Estimated Time:45s
Question 40Question →

With reference to Indian space technology, launch vehicles, and space exploration missions, consider the following statements:

1. The Polar Satellite Launch Vehicle (PSLV) is a four-stage vehicle using alternating solid and liquid propulsion systems, with the first and third stages powered by solid motors.
2. The Launch Vehicle Mark-3 (LVM3) consists of twin solid strap-on motors (S200), a core liquid stage (L110), and an indigenous cryogenic upper stage (C25).
3. The Aditya-L1 spacecraft is placed in a halo orbit around the Earth-Moon Lagrangian point 1 (L1L_1) to ensure continuous, unobstructed observation of solar activity.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1 and 2 only

Answer

Statements 1 and 2 are correct, while statement 3 is incorrect.
The combination '1 and 2 only' is correct. PSLV operates with four alternating solid/liquid stages (1st and 3rd solid, 2nd and 4th liquid). LVM3 utilizes twin S200 solid strap-ons, an L110 core liquid stage, and a C25 cryogenic upper stage. Statement 3 is false because Aditya-L1 orbits the Sun-Earth L1L_1 point, not the Earth-Moon L1L_1 point.

Step-by-Step Solution

1
Evaluate Statement 1 regarding PSLV propulsion stages.
PSLV is a 4-stage vehicle featuring alternating solid and liquid stages: PS1 (Solid), PS2 (Liquid - Vikas Engine), PS3 (Solid), and PS4 (Liquid). Thus, statement 1 is correct.
Verify stage configuration of India's workhorse launch vehicle.
2
Evaluate Statement 2 regarding LVM3 architecture.
LVM3 features two heavy solid strap-on boosters (S200), a central liquid propellant core stage (L110), and a high-thrust cryogenic upper stage (C25). Thus, statement 2 is correct.
Verify heavy-lift launch vehicle payload and propulsion stages.
3
Evaluate Statement 3 regarding Aditya-L1 orbital mechanics.
Aditya-L1 is stationed in a halo orbit surrounding the Sun-Earth Lagrangian Point 1 (L1L_1), located approximately 1.5 million kilometers from Earth, NOT the Earth-Moon Lagrangian point. Thus, statement 3 is incorrect.
Differentiate between Sun-Earth and Earth-Moon system Lagrange points.

Key Concept

ISRO Launch Vehicle Propulsion Stages and Deep Space Mission Orbit Dynamics
PreviousPage 2 / 12Next
General Science and Technology Practice Questions — State PSC Exam — Page 2 | Examkin