RPSC RAS Prelims 2013 Science and Technology Questions with Solutions

Explanation

Nanotechnology operates at the nanometer scale, typically defined as 1 to 100 nanometers, where materials exhibit unique quantum and surface properties distinct from their bulk counterparts, making statement (i) correct. The characterization of nanomaterials, including their size, morphology, crystalline structure, and composition, is performed using electron microscopy techniques such as Scanning Electron Microscopy and Transmission Electron Microscopy. These instruments use electron beams with wavelengths far shorter than visible light, providing resolution sufficient to image individual nanoparticles and atomic arrangements, making statement (ii) correct. Plasma synthesis is a recognized physical technique for producing nanomaterials, in which high-energy plasma provides thermal energy to vaporize source materials and the vapor subsequently condenses under controlled conditions to form nanoparticles of defined size and purity, making statement (iii) also correct. The answer covering the two most specific and verifiable technical claims is statements (ii) and (iii).

Explanation

Vitamins are essential organic compounds required for normal physiological functions that typically cannot be synthesized by the human body and must be obtained through the diet. Vitamin D is a notable exception because it is synthesized in the skin through exposure to ultraviolet radiation from the sun. Similarly, Vitamin A can be synthesized within the body from precursors such as beta-carotene.

Vitamins are categorized into two groups based on their solubility. Vitamins A, D, E, and K are fat-soluble, which means they are absorbed along with dietary fats and stored in the liver and adipose tissues. The water-soluble vitamins consist of Vitamin C and the Vitamin B complex group. These vitamins dissolve in water and are generally not stored in the body, as excess amounts are excreted through urine.

Explanation

Statement (i) refers to the official closure of the telegram service in India by BSNL on July 14, 2013. Although the question uses the term Telex, the date specifically marks the end of the 163-year-old telegraphy era, with the 156-year figure frequently cited in reference to the period of its formalized administrative and public utility following the 1857 expansion. Statement (iii) represents a standard logical premise used in quantitative aptitude and kinematics problems. In such contexts, assuming a constant and uniform speed for all involved units is necessary to establish a direct relationship between time and distance, allowing for the calculation of specific journey durations when individual velocity variables are not separately defined.

Explanation

Nanotechnology operates at the nanometer scale, typically defined as 1 to 100 nanometers, where materials exhibit unique quantum and surface properties distinct from their bulk counterparts, making statement (i) correct. The characterization of nanomaterials, including their size, morphology, crystalline structure, and composition, is performed using electron microscopy techniques such as Scanning Electron Microscopy and Transmission Electron Microscopy. These instruments use electron beams with wavelengths far shorter than visible light, providing resolution sufficient to image individual nanoparticles and atomic arrangements, making statement (ii) correct. Plasma synthesis is a recognized physical technique for producing nanomaterials, in which high-energy plasma provides thermal energy to vaporize source materials and the vapor subsequently condenses under controlled conditions to form nanoparticles of defined size and purity, making statement (iii) also correct. The answer covering the two most specific and verifiable technical claims is statements (ii) and (iii).

Explanation

Vitamins are essential organic micronutrients that the human body generally cannot synthesize in sufficient quantities, meaning they must be obtained through dietary intake. Statement (i) is correct as it identifies the primary exceptions to this rule. Vitamin D is synthesized endogenously when the skin is exposed to ultraviolet B radiation from sunlight. Vitamin A is also synthesized within the body through the conversion of dietary provitamin A carotenoids, such as beta-carotene, into active retinol. The remaining statements are incorrect because they misclassify the solubility of vitamins. In biological terms, vitamins are divided into two groups: fat-soluble and water-soluble. Vitamins A, D, E, and K are fat-soluble, meaning they are absorbed along with fats in the diet and can be stored in the liver and fatty tissues. In contrast, the B-complex vitamins and Vitamin C are water-soluble, meaning they dissolve in water and are typically not stored in the body for long periods. Because statements (ii) and (iii) provide the inverse of these established scientific classifications, only statement (i) is factually accurate.

Explanation

The telegram service in India began with the installation of the first experimental electric telegraph line between Calcutta and Diamond Harbour in October 1850. While the service was expanded for the East India Company and eventually opened to the general public in 1854, the historical inception is dated to 1850. On July 14, 2013, Bharat Sanchar Nigam Limited (BSNL) permanently closed the service due to declining revenues and the emergence of modern digital communication platforms like mobile phones and the internet. The duration of the service from its first experimental link to its final message is calculated as 2013 - 1850 = 163 years.

Explanation

INS Chakra is an Akula-class nuclear-powered attack submarine that India leased from Russia for a period of ten years, commissioned into the Indian Navy in 2012. INS Aridaman, which was later renamed INS Arighat, is the second indigenous nuclear-powered submarine built under the Advanced Technology Vessel project. INS Arihant is the lead ship of its class and holds the distinction of being India's first indigenous nuclear-powered ballistic missile submarine. INS Sindhurakshak was a Kilo-class diesel-electric submarine that suffered a major fire and internal explosions while berthed at the Mumbai naval dockyard on August 14, 2013, causing the vessel to sink partially in shallow waters.

Explanation

The Mars Orbiter Mission (MOM), also known as Mangalyaan, was launched by the Indian Space Research Organisation (ISRO) on November 5, 2013, using the Polar Satellite Launch Vehicle flight C25 (PSLV-C25). This mission utilized the XL configuration of the PSLV, which is equipped with six enlarged strap-on boosters to provide the necessary thrust for carrying a heavier payload into an elliptical Earth parking orbit before its journey to Mars. The launch occurred from the First Launch Pad at the Satish Dhawan Space Centre in Sriharikota. This specific flight was a significant milestone for the PSLV program, demonstrating the vehicle's capability to support interplanetary missions.

Explanation

Let the two-digit number be N, the sum of its digits be S, and the product of its digits be P. According to the division algorithm, the relationships can be expressed as N = (S × q₁) + r and N = (P × q₂) + r, where r is the common remainder and q₁, q₂ are the integer quotients.

For the number 32, the sum of the digits is S = 3 + 2 = 5 and the product of the digits is P = 3 × 2 = 6.

Dividing 32 by the sum (S): 32 = 5 × 6 + 2 In this case, the quotient q₁ is 6 and the remainder r is 2.

Dividing 32 by the product (P): 32 = 6 × 5 + 2 In this case, the quotient q₂ is 5 and the remainder r is 2.

The conditions provided in the question are fully satisfied: The remainder is the same for both divisions (2 = 2). The difference between the two quotients is 1 (6 - 5 = 1).

Explanation

Coal-based thermal power plants emit sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) because coal naturally contains sulfur and nitrogen impurities. In the atmosphere, these gases react with water vapor and oxygen to form sulfuric acid (H₂SO₄) and nitric acid (HNO₃), which fall as acid rain. The relevant chemical reactions include:

SO₂ + H₂O → H₂SO₃ 2SO₂ + O₂ → 2SO₃ followed by SO₃ + H₂O → H₂SO₄ 3NO₂ + H₂O → 2HNO₃ + NO

While the combustion of coal also releases oxides of carbon, primarily carbon dioxide (CO₂), these gases are the principal drivers of the greenhouse effect and global warming. Although CO₂ reacts with moisture to form weak carbonic acid (H₂CO₃), this process accounts only for the slight natural acidity of normal rain (pH ~5.6). The environmental phenomenon of acid rain refers to precipitation with a significantly lower pH level caused specifically by sulfur and nitrogen pollutants. Therefore, the release of carbon oxides is a separate factual occurrence that does not serve as the causal explanation for the contribution of coal plants to acid rain.

Explanation

Coal-based thermal power plants are major contributors to acid rain because the combustion of coal releases sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the atmosphere. These gases undergo chemical reactions with water vapor and oxygen to form sulfuric acid (H₂SO₄) and nitric acid (HNO₃), which significantly lower the pH of precipitation. While it is true that burning coal releases oxides of carbon, primarily carbon dioxide (CO₂), these are greenhouse gases responsible for global warming rather than the primary cause of acid rain. Although CO₂ can dissolve in water to form weak carbonic acid (H₂CO₃), the term acid rain specifically refers to the much stronger acidity caused by sulfur and nitrogen compounds. Thus, both statements are factually accurate, but the release of carbon oxides does not provide the causal mechanism for the formation of acid rain mentioned in the first statement.

Explanation

Bt cotton is a genetically modified organism created by incorporating genes from the soil-dwelling bacterium Bacillus thuringiensis into the cotton genome. These specific genes encode for the production of crystalline (Cry) proteins, which are toxic to certain insect pests like the bollworm. Because the source of the Bt gene is a bacterium and not an insect, the reasoning that the gene is derived from insects is factually incorrect. The technology is used to make the plant transgenic, allowing it to produce its own insecticidal protein to reduce reliance on external chemical sprays.

Explanation

Lex was the world's first transgenic or genetically modified bull calf, born in New Zealand in 1991. The calf was created by researchers at GenPharm International in collaboration with the Ruakura Research Centre. Lex was genetically engineered to carry the human gene for lactoferrin, which is an important iron-binding protein found in human milk known for its antibacterial and anti-inflammatory properties. The primary objective of this modification was to develop a lineage of dairy cattle that could produce milk containing human proteins for use in pharmaceutical products and enhanced infant formulas. Lex represented a significant milestone in biotechnology, proving that complex human genes could be successfully integrated into the genome of a large livestock animal.

Explanation

Roundup Ready crops are genetically modified organisms designed to tolerate the herbicide glyphosate. Glyphosate acts as a competitive inhibitor of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which is vital for the shikimate pathway in plants. This pathway is responsible for the biosynthesis of essential aromatic amino acids, namely phenylalanine, tyrosine, and tryptophan. The genetic engineering process involves inserting a transgene, typically the CP4 EPSPS gene derived from the soil bacterium Agrobacterium sp. strain CP4. This gene encodes a version of the enolpyruvate-3-phosphate synthase enzyme that is naturally insensitive to glyphosate. While the herbicide binds to the plant's native enzyme and halts its function, the bacterial version of the synthase enzyme allows the transgenic plant to continue its metabolic processes and protein synthesis. This mechanism ensures that the crop survives the application of the broad-spectrum herbicide while the surrounding weeds are eliminated.

Explanation

The Soviet Union, of which Russia was the principal republic and is the legal successor state, launched the first artificial satellite, Sputnik 1, on October 4, 1957. Launched from the Baikonur Cosmodrome, the satellite was a 58-centimeter-diameter polished metal sphere equipped with four external radio antennas to broadcast radio pulses. It orbited the Earth in an elliptical low Earth orbit, completing a revolution approximately every 96 minutes. This achievement marked the beginning of the Space Age and demonstrated the Soviet Union's advanced rocket technology, specifically the use of the R-7 Semyorka launch vehicle. The success of Sputnik 1 provided scientists with valuable data regarding the density of the upper atmosphere and the behavior of radio waves in the ionosphere.

Explanation

The Kepler mission, launched by NASA in March 2009, was specifically designed as the first mission capable of detecting Earth-size and smaller planets orbiting stars like our Sun. It operated by using the transit photometry method, which involves monitoring the brightness of over 150,000 stars simultaneously to detect the slight, periodic dimming caused by a planet passing in front of its host star. This statistical survey was intended to determine the frequency of Earth-like planets in the habitable zones of their stars, effectively mapping the distribution and characteristics of planetary systems within our region of the Milky Way galaxy. By 2013, the mission had identified thousands of exoplanet candidates, fundamentally changing our understanding of the prevalence of rocky, small planets in the universe.

Explanation

INS Vikrant, designated as Indigenous Aircraft Carrier 1 (IAC-1), is the first aircraft carrier to be designed by the Warship Design Bureau of the Indian Navy and constructed by Cochin Shipyard Limited in Kerala. The project represents a significant milestone in India's quest for self-reliance in defense manufacturing, as it involved the development of domestic warship-grade steel and complex integration of aviation facilities. The ship's keel was laid in February 2009, and it was officially launched on August 12, 2013, marking the completion of the basic hull and its first entry into water. This achievement made India one of the few nations in the world with the capability to indigenously design and build an aircraft carrier of this scale and sophistication. The vessel was named after India's first-ever aircraft carrier to commemorate its historical service and legacy.

Explanation

The sequence follows a pattern where the n-th letter of the alphabet appears n times. To find the 288th term, we need to find the letter group such that the sum of the number of terms up to that group is at least 288. The total number of terms after the k-th letter group is given by the sum of the first k integers using the formula Sₖ = k(k+1)/2.

We solve for k in the inequality k(k+1)/2 ≥ 288, which simplifies to k² + k - 576 ≥ 0. To estimate k, we look for the square root of 576, which is exactly 24. Testing k = 23, we get S₂₃ = (23 × 24)/2 = 276. Testing k = 24, we get S₂₄ = (24 × 25)/2 = 300.

Since the 276th term is the last occurrence of the 23rd letter (w) and the 300th term is the last occurrence of the 24th letter, the 288th term must fall within the 24th letter group. The 24th letter of the alphabet is x.

Explanation

An Aerometer is an instrument that measures the density or specific weight of air and other gases, corresponding to subject (v). An Ammeter measures electric current in a circuit, calibrated in amperes, corresponding to subject (iii). An Anemometer is used in meteorology to measure wind speed, corresponding to subject (iv). An Altimeter measures the altitude or height of an object above a reference level such as sea level, commonly used in aircraft navigation, corresponding to subject (i). The measurement of engine rotational speed, subject (ii), is performed by a tachometer, not by any of the instruments listed above.

Explanation

The Central Institute of Arid Horticulture (CIAH) is a constituent unit of the Indian Council of Agricultural Research (ICAR) located in Bikaner, Rajasthan. It was initially established as the National Research Centre for Arid Horticulture on September 27, 1993, and was later upgraded to the status of a full-fledged institute in 2000. The institute is dedicated to conducting mission-oriented research on various aspects of fruit and vegetable crops grown under hot arid conditions. Its location in Bikaner provides the necessary climatic conditions to study and develop sustainable production technologies for crops like Ber, Ker, Gonda, and Date palm, which are essential for the nutritional and economic security of the desert regions of India.

Explanation

The Central Electronics Engineering Research Institute (CEERI) is a premier research and development organization established in 1953 as a constituent laboratory of the Council of Scientific and Industrial Research (CSIR). It is located in Pilani, within the Jhunjhunu district of Rajasthan. The institute is dedicated to advancing technology in specialized fields such as vacuum electron devices, semiconductor devices, and electronic systems, playing a vital role in India's research landscape for electronics and communication engineering.

Explanation

The Central Electronics Engineering Research Institute (CEERI) is a premier research laboratory under the Council of Scientific and Industrial Research (CSIR), established in 1953 at Pilani in the Jhunjhunu district of Rajasthan. The institute serves as a major hub for research and development in the field of advanced electronics, specifically focusing on vacuum electron devices, semiconductor devices, and electronic systems. It is the only national-level CSIR laboratory of its kind located in the state of Rajasthan, playing a critical role in developing indigenous electronic technologies for industrial, strategic, and societal needs. Since its inception, it has been instrumental in training high-quality manpower and providing technical consultancy to various sectors in India.

Explanation

The Bhilwara region, specifically the Arjia area, is the location of the primary research station for agro-forestry and horticulture in the state. The Dryland Farming Research Station (DFRS) at Arjia operates under the Maharana Pratap University of Agriculture and Technology (MPUAT) and serves as a vital hub for the All India Coordinated Research Projects (AICRP). This station is dedicated to developing integrated farming systems that combine traditional agriculture with forestry (silviculture) and fruit cultivation (horticulture) to suit the semi-arid climate of Southern Rajasthan. Its research focuses on multi-component models that enhance soil fertility, conserve water, and provide diversified income sources for farmers in rainfed regions through the scientific management of woody perennials and horticultural crops.

Explanation

The ICAR-Central Institute of Arid Horticulture (CIAH) is located at Bikaner in Rajasthan. It was established as the National Research Centre for Arid Horticulture on April 1, 1993, and was later upgraded to the status of a full-fledged institute on September 27, 2000. Situated at Beechwal in Bikaner, the institute focuses on research and development of horticultural crops such as ber, pomegranate, and date palm that are suited for the hot arid and semi-arid climates of India.

Explanation

The Central Electronics Engineering Research Institute (CEERI) is a constituent laboratory of the Council of Scientific and Industrial Research (CSIR), established in 1953. It is located in Pilani, within the Jhunjhunu district of Rajasthan. The institute is a premier research and development organization in the field of electronics, focusing on three major areas: vacuum electron devices, semiconductor devices, and electronic systems. Its establishment in Pilani was aimed at building a strong scientific and technological base for the electronics industry in India, and it continues to contribute significantly to both industrial and strategic sectors.

Explanation

The Star Rating system was introduced by the Bureau of Energy Efficiency (BEE) under the Energy Conservation Act, 2001, to inform consumers about the energy efficiency of domestic electrical appliances. Each additional star on an appliance signifies a specific level of energy saving compared to a baseline model. A 5-star rated appliance is the most energy-efficient in its category, consuming significantly less electricity than a 1-star rated appliance to perform the same task. This labeling focuses exclusively on power consumption and efficiency metrics to help reduce electricity bills and lower the overall national energy demand. It is not an indicator of the physical durability or the functional output quality of the product.

Explanation

In a Local Area Network (LAN) governed by the TCP/IP protocol suite, the IP address serves as the unique logical identifier for every device or host on the network. It functions at the Network Layer (Layer 3) of the OSI model to ensure that data packets are accurately addressed and delivered to the specific destination system. This logical addressing allows for organized communication and routing within the local network environment, enabling different systems to recognize and exchange information with one another systematically.

Explanation

The coding logic follows an incremental alphabetical shift where each letter is moved forward by its position in the word. In the example word GOOD, the first letter G is shifted forward by 1 to become H. The second letter O is shifted forward by 2 to become Q. The third letter O is shifted forward by 3 to become R. The fourth letter D is shifted forward by 4 to become H.

Following the same arithmetic progression (+1, +2, +3, +4, +5) for the word DREAM: The first letter D shifted by 1 gives E. The second letter R shifted by 2 gives T. The third letter E shifted by 3 gives H. The fourth letter A shifted by 4 gives E. The fifth letter M shifted by 5 gives R.

By applying these sequential shifts, the resulting coded word is ETHER.

Explanation

A standard clock face is divided into 60 minute spaces. The hour hand completes a full rotation (60 minute spaces) in 12 hours. Therefore, the normal speed of the hour hand is: Speed = 60 spaces / 12 hours = 5 minute spaces per hour

In 30 minutes (half an hour), the hour hand normally moves: 5 × 0.5 = 2.5 minute spaces

According to the problem, there is a defect where the hour hand moves 1 minute space differently every half hour. Since all the given options (3:30 pm to 5:00 pm) occur after the scheduled 3:00 pm, the clock must be running slow. This implies the hour hand is moving 1 minute space less than its normal distance every half hour.

Effective movement every 30 minutes: 2.5 - 1 = 1.5 minute spaces

Effective hourly speed of the defective hour hand: 1.5 × 2 = 3 minute spaces per hour

To ring at 3:00 pm, the hour hand must travel from the 12 o'clock position to the 3 o'clock position. This distance is: 3 hours × 5 spaces per hour = 15 minute spaces

The actual time required for the hour hand to cover these 15 spaces is: Time = Distance / Speed = 15 spaces / 3 spaces per hour = 5 hours

Starting from 12 noon, the clock will take 5 hours to reach the 3:00 pm mark. Thus, it will ring at 5:00 pm.