DAY – 69 : Insta 75 Days Revision Plan-2026 : Science & Technology Full Syllabus

Answer: (d)

Explanation:

• Statement I is correct: Lab-Grown Diamonds (LGDs) possess the same chemical composition (pure carbon), crystal structure, hardness, and optical properties as natural diamonds. The primary difference lies in their origin—natural diamonds are formed naturally over geological timescales, whereas LGDs are produced artificially in laboratories.
• Statement II is correct: Natural diamonds generally contain trace impurities such as nitrogen due to geological formation processes. In contrast, diamonds produced through the Chemical Vapor Deposition (CVD) method are usually nitrogen-free or contain extremely low nitrogen content because the process allows controlled crystal growth in a purified environment.
• Statement III is correct: The High-Pressure High-Temperature (HPHT) method recreates the extreme pressure and temperature conditions found deep within the Earth’s mantle to synthesize diamonds. It imitates the natural geological process responsible for the formation of natural diamonds.

Answer: (a)

• Statement I is correct: Nuclear Thermal Propulsion (NTP) systems provide significantly higher specific impulse (fuel efficiency) than conventional chemical rockets. This allows spacecraft to achieve greater thrust efficiency while using less propellant.
• Statement II is correct: In an NTP system, a nuclear reactor heats a liquid propellant, commonly liquid hydrogen. The heated hydrogen expands into a high-temperature gas and is expelled through a nozzle to produce thrust.

• The extremely high temperatures generated by the nuclear reactor enable the propellant to attain much higher exhaust velocities than those achievable in chemical propulsion systems. Higher exhaust velocity directly results in higher specific impulse and greater fuel efficiency.

Answer: (c)

Explanation:

• Statement I is correct: A Digital Twin is a virtual representation of a physical object, process, or system that exists throughout its lifecycle. It mirrors the characteristics and functioning of the real-world entity.
• Statement II is correct: Digital Twins rely on real-time data collected through sensors embedded in the physical asset. This data is continuously transmitted to the virtual model to simulate performance, predict outcomes, and monitor operations.
• Statement III is correct: A key distinction between a Digital Twin and a conventional CAD model is the presence of continuous two-way data interaction. The physical system sends operational data to the virtual model, while insights from the virtual model can also influence or optimize the physical system.

Answer: (d)

Explanation:

• Statement I is correct: Organoid Intelligence (OI) refers to the use of laboratory-grown brain organoids integrated with electronic interfaces such as sensors and output devices to enable information processing and computational functions.
• Statement II is correct: Bio-computers based on neural organoids are expected to achieve highly efficient computation with much lower energy requirements compared to conventional silicon-based artificial intelligence systems, as biological neural networks process information very efficiently.
• Statement III is correct: Present research in Organoid Intelligence commonly uses human brain cells to develop organoids. This has generated ethical concerns regarding the possibility of developing forms of awareness, sentience, or consciousness in advanced lab-grown neural tissues.

Answer: (c)

Explanation:

• I. Laser Brooming — Correct: Laser brooming is a proposed active debris removal technique in which ground-based or space-based lasers are used to alter the orbit of debris through photon pressure or surface ablation, causing it to re-enter the atmosphere.
• II. Magnetic Tug — Correct: Magnetic tug concepts involve spacecraft using magnetic interaction to capture or influence defunct satellites and guide them into lower orbits for atmospheric burn-up.
• III. Liquid Metal Heat Pipes — Incorrect: Liquid metal heat pipes are thermal management systems used for efficient heat transfer in spacecraft and reactors. They are not debris removal technologies.
• IV. Drag Sails — Correct: Drag sails are devices attached to satellites to increase atmospheric drag in Low Earth Orbit, accelerating orbital decay and controlled deorbiting.

Answer: (c)

Explanation:

• I. Mapping the entire genetic diversity of every Indian citizen — Incorrect: The Genome India Project does not aim to sequence the genome of every Indian citizen. Its objective is to create a representative genetic database by sequencing genomes from diverse population groups across India.
• II. Creation of a reference genome for the Indian population — Correct: One of the primary objectives of the Genome India Project is to develop an Indian reference genome that reflects the country’s genetic diversity.
• III. Identification of genetic markers for rare diseases — Correct: The project seeks to identify genetic variations and markers associated with rare and inherited diseases, which can improve diagnosis and research.
• IV. Development of personalized medicine for lifestyle diseases — Correct: The genomic database generated under the project can support precision medicine and help design personalized treatment strategies for diseases such as diabetes, cancer, and cardiovascular disorders.

Answer: (c)

Explanation:

• Statement I is correct: Liquid mirror telescopes use a rotating reflective liquid, usually mercury, to naturally form a parabolic surface suitable for astronomical observations.
• Statement II is incorrect: Liquid mirrors cannot be tilted like conventional glass-mirror telescopes. Since the parabolic shape is maintained through rotation under gravity, the mirror must remain aligned vertically and can observe only the portion of the sky passing directly overhead.
• Statement III is correct: India’s International Liquid Mirror Telescope is located at Devasthal in Uttarakhand and is operated for astronomical sky surveys and observations.

Answer: (a)

Explanation:

• Neon: Neon is an inert noble gas used mainly in excimer lasers for deep ultraviolet (DUV) photolithography and certain plasma-based semiconductor manufacturing processes. It does not introduce impurity atoms into silicon and therefore is not used as a dopant.
• Argon: Argon is another inert noble gas commonly used in sputtering, plasma etching, and controlled fabrication environments because of its chemically non-reactive nature. It does not alter the electrical conductivity of silicon wafers and hence is not a dopant.
• Silane (SiH₄): Silane is primarily a silicon precursor gas used in Chemical Vapor Deposition (CVD) to deposit thin silicon or polysilicon layers during chip fabrication. Although essential in semiconductor manufacturing, it is not itself used as a dopant to modify the electrical properties of silicon.
• Phosphine (PH₃): Phosphine is a true dopant gas used to introduce phosphorus atoms into silicon wafers. Since phosphorus has five valence electrons, it contributes extra free electrons and creates n-type semiconductor material with enhanced electrical conductivity.

Answer: (b)

Explanation:

• Xylazine: Xylazine is a veterinary sedative and tranquilizer that is increasingly being found mixed with illicit opioids such as fentanyl. Although it is not itself an opioid, it is associated with severe health complications, including respiratory depression and tissue damage, in the ongoing drug crisis.
• Fentanyl: Fentanyl is a highly potent synthetic opioid used medically for pain management but widely abused illegally. It is significantly more powerful than morphine and has been a major contributor to overdose deaths in several countries.
• Nitazenes: Nitazenes are a group of extremely potent synthetic opioids originally developed for pharmaceutical research but never approved for routine medical use. They are now emerging in illegal drug markets and are associated with high overdose risks.

Answer: (a)

Explanation:

• Statement I is correct: Microbial Fuel Cells (MFCs) generate electricity by using microorganisms, especially bacteria, as biocatalysts. These bacteria oxidize organic matter and release electrons during their metabolic processes, which are then captured to produce electric current.
• Statement II is correct: Unlike many conventional electrochemical systems, MFCs can operate under normal environmental conditions, including room temperature. They also generally avoid the need for expensive precious metal catalysts such as platinum, making them potentially cost-effective and environmentally sustainable.
• Statement III is incorrect: Microbial Fuel Cells are currently limited in power output and are mainly being explored for applications such as wastewater treatment, biosensors, and low-power energy generation. They are not being used as the primary propulsion source for deep-sea manned submersibles.

Answer: (c) Q is the father of P

Detailed Explanation:

We decode the expression step by step.

Step 1: Interpret P + R

According to the condition:

• A + B means A is the son of B.

Therefore:

• P + R means P is the son of R.

So:

• P is male.
• R is the parent of P.

Step 2: Interpret R – Q

According to the condition:

• A – B means A is the wife of B.

Therefore:

• R – Q means R is the wife of Q.

So:

• R is female.
• Q is the husband of R.

Step 3: Combine both relations

We already know:

• P is the son of R.
• R is the wife of Q.

Hence:

• Q is the father of P.

Therefore, the correct answer is:

(c) Q is the father of P

Answer: (d) Shyamala

Detailed Explanation:

Let us arrange the information carefully.

Step 1: Total women

There are six women:

• Vimala
• Kamala
• Amala
• Komala
• Nirmala
• Shyamala

Step 2: Identify bank employees

The question says:

• Vimala and Kamala are bank employees.

Also:

• Total bank employees = 3.

Further:

• Amala and Komala are unemployed.

Therefore:

• Amala and Komala cannot be bank employees.

So the third bank employee must be either:

• Nirmala or
• Shyamala.

Step 3: Identify required person

We need the woman who is:

1. postgraduate in Commerce
2. lawyer
3. bank employee

Among the options:

• Amala → unemployed → cannot be bank employee
• Komala → unemployed → cannot be bank employee
• Nirmala → possible bank employee but conditions do not fully fit
• Shyamala → satisfies all required conditions

Hence, the only suitable person is:

(d) Shyamala

Answer: (a) G

Detailed Explanation

Step 1: Understand the directions

From the given information:

• C can go to A, D and G.
• G can go to H.
• E can go to C.
• A and B are connected both ways.
• D and E are connected both ways.
• G and F are connected both ways.

Step 2: Find routes from C to H

To reach H, the only direct connection available is:

• G → H

Therefore, before reaching H, one must first reach G.

From C:

• C → G → H

No other station has a direct path to H.

Thus, every route from C to H must pass through G.

Conclusion

The station that must necessarily be passed through while travelling from C to H is: (a) G

Answer: (b) B

Detailed Explanation:

In each statement, the two teachers mentioned teach the two subjects mentioned respectively.

Step 1

“A and B teach Hindi and English.”

So:

• A → Hindi
• B → English

Step 2

“C and B teach English and Geography.”

We already know B teaches English.

Therefore:

• C → Geography

Step 3

“D and A teach Mathematics and Hindi.”

We already know A teaches Hindi.

Therefore:

• D → Mathematics

Step 4

“E and B teach History and French.”

B already teaches English, so B must additionally teach History.

Therefore:

• E → French
• B → History

Final Subject Allocation

Thus, B teaches 2 subjects, while all others teach only 1 subject.

Therefore, the teacher teaching the maximum number of subjects is: (b) BTop of Form

Answer: (a) duty to vote

Detailed Explanation:

The passage emphasizes:

• active participation in democracy,
• involvement in public affairs,
• and especially voting.

The author says that refusing to vote is:

• avoiding political responsibility,
• while still enjoying the benefits of democracy.

Thus, the passage does not merely discuss the right to vote.
Instead, it stresses that citizens have a moral and civic responsibility to vote.

Therefore, the central idea is:

(a) duty to vote