Explanation : 

Statement II is true – activated carbon has a highly porous structure (surface areas up to 1 000–2 000 m²/g) that makes it an excellent adsorbent for heavy‐metal ions and other dissolved pollutants. Statement III is also true – one can prepare activated carbon cheaply by pyrolyzing and activating high‐carbon wastes (coconut shells, nutshells, sawdust, sewage sludge, etc.).

Together, (II) explains why activated carbon is so effective at removing contaminants (its huge surface area and affinity for metals), and (III) explains why it is an attractive (i.e. low‐cost, sustainable) tool, thus both support Statement I.

Explanation : 

Statement I is false – Viruses are abundant in ocean waters, especially bacteriophages (viruses that infect bacteria). Marine viruses are known to be extremely numerous and play a significant role in marine ecosystems.

Statement II is false – bacteriophages are viruses that specifically infect bacteria.

Statement III is false – many viruses (e.g. herpesviruses, retroviruses) encode proteins or RNAs that reprogram host‐cell transcription.

Explanation : 

The correct answer is (d) – all three statements are true.

1. Monoclonal antibodies are indeed “man-made” (i.e. laboratory-produced) proteins: ‑ Starting from a single immune B-cell clone, they are engineered (often in mice, humanized or fully human cell-lines) to yield a homogeneous population of identical antibody molecules.

2. Their key feature is high specificity: ‑ Each monoclonal antibody binds a single, unique epitope on its target antigen. ‑ By occupying that epitope, they can block receptor–ligand interactions or flag the antigen for destruction by other immune cells, thereby modulating immune function.

3. They are used (and are in development) against several viral infections, including Nipah: ‑ Examples already in clinical use include palivizumab for RSV, REGN-EB3 (Inmazeb) for Ebola, various mAbs for COVID-19. ‑ For Nipah virus, the mAb known as m102.4 has been given on a compassionate-use basis in outbreaks and is in clinical trials.

Explanation : 

Majorana 1 quantum chip

The Majorana 1 quantum chip, introduced by Microsoft (not Amazon Web Services), represents a significant advancement in quantum computing through its use of topological qubits, which enhance stability and scalability.

Deep learning is a specialized area within machine learning that utilizes neural networks composed of multiple interconnected layers to model complex patterns and relationships in large datasets effectively.

Explanation : 

CL-20, HMX and LLM-105

CL-20 (hexanitrohexaazaisowurtzitane), HMX (octogen) and LLM-105 are all high-performance military explosives. They are prized for their very high detonation velocities and pressures and are used in advanced warheads, shaped charges and propellant formulations. They are not refrigerants or conventional fuels.

Explanation : 

Coal gasification

Coal gasification produces a synthesis gas (syngas) mixture of CO and H₂, which serves as a versatile building-block for many downstream chemicals:

Ethanol
– Syngas → (Fischer–Tropsch or direct catalytic) → ethanol
– Or via syngas fermentation by specialized microbes

Nitroglycerine
– Syngas → NH₃ (Haber–Bosch) → HNO₃ (Ostwald process)
– HNO₃ + glycerol → nitroglycerine (nitration)

Urea
– Syngas → NH₃
– Syngas also supplies CO₂
– NH₃ + CO₂ → ammonium carbamate → urea

Since all three—ethanol, nitroglycerine (via HNO₃ from NH₃), and urea—can be derived ultimately from coal-derived syngas, the correct answer is (c) all three.

Explanation :

I. Cigarette butts: Cigarette butts contain cellulose acetate, a type of plastic.

II. Eyeglass lenses: Most modern eyeglass lenses are made from plastic materials such as polycarbonate or CR-39 (plastic polymer).

III. Car tyres: Car tyres contain synthetic rubber, which is a polymer-based plastic material.

Thus, all three items listed contain plastic.

Explanation : 

In lithium-ion batteries used in electric vehicles, the battery cell primarily consists of two electrodes: the cathode (positive electrode) and the anode (negative electrode).

Cathode (Positive Electrode):

The cathode typically contains lithium-based metal oxides. Common cathode materials include:

Lithium (Li): Essential component in cathode materials, present as lithium ions.
Cobalt (Co): Used in cathodes such as Lithium Cobalt Oxide (LiCoO₂).
Nickel (Ni): Used in cathodes such as Nickel-Manganese-Cobalt (NMC) or Nickel-Cobalt-Aluminum (NCA) chemistries.

Thus, Lithium, Cobalt, and Nickel are commonly found in cathode materials.

Anode (Negative Electrode):

The anode typically consists of carbon-based materials, most commonly:

Graphite: Widely used as the anode material due to its ability to intercalate lithium ions efficiently.

Hence, the correct answer is option (c) Only three.

Explanation : 

I. “All types of UAVs can do vertical landing.” This statement is incorrect. UAVs come in various types, such as fixed-wing UAVs, rotary-wing UAVs (multirotors), and hybrid UAVs. Fixed-wing UAVs typically require a runway or landing strip and cannot perform vertical landings. Only rotary-wing or hybrid UAVs can perform vertical landings.

II. “All types of UAVs can do automated hovering.” This statement is incorrect. Fixed-wing UAVs cannot hover in place because they rely on forward motion to generate lift. Only rotary-wing UAVs (such as quadcopters or helicopters) or certain hybrid UAVs can hover.

III. “All types of UAVs can use battery only as a source of power supply.” This statement is incorrect. While many small UAVs use batteries, larger UAVs or specialized UAVs may use other power sources such as gasoline engines, hybrid power systems, solar power, or fuel cells.

Thus, none of the given statements are correct.

Explanation : 

Alternative powertrain vehicles

Alternative powertrain vehicles refer to vehicles that use propulsion systems other than conventional internal combustion engines powered solely by gasoline or diesel. The given types of vehicles are:

I. Full battery electric vehicles (BEVs): These vehicles run entirely on electricity stored in batteries and do not use conventional fuels.

II. Hydrogen fuel cell vehicles (FCVs): These vehicles use hydrogen gas to generate electricity through fuel cells, powering an electric motor. They emit only water vapor as exhaust.

III. Fuel cell electric hybrid vehicles: These vehicles combine hydrogen fuel cell technology with battery-electric technology, using both fuel cells and batteries to power the vehicle.

All three types mentioned above represent alternative powertrain technologies, as they deviate from traditional internal combustion engine vehicles. Hence, the correct answer is option (c) All the three.