UPSC CDS-1 Archives

1. Which one of the following is not an exclusive right of the concerne

Which one of the following is not an exclusive right of the concerned coastal nations over Exclusive Economic Zone (EEZ)?

[amp_mcq option1=”Survey and exploitation of mineral resources of ocean deposits” option2=”Exploitation of marine water energy and marine organisms including fishing” option3=”Conservation and management of marine resources” option4=”Navigation of ships and laying down submarine cables” correct=”option4″]

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UPSC CDS-1 – 2018

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The Exclusive Economic Zone (EEZ) extends up to 200 nautical miles from the baseline of a coastal state. Within this zone, the coastal state has sovereign rights for the purpose of exploring and exploiting, conserving and managing natural resources (living and non-living) of the waters, seabed, and subsoil (options A, B, C). However, UNCLOS grants all states certain freedoms in the EEZ, including the freedom of navigation, overflight, and the laying of submarine cables and pipelines. These are not exclusive rights of the coastal nation but rather high seas freedoms exercised within the EEZ, compatible with the coastal state’s rights. Therefore, navigation of ships and laying down submarine cables are not exclusive rights.

– The EEZ grants coastal states sovereign rights over resources but not full sovereignty over the water column or airspace.
– Freedoms of navigation and laying submarine cables are preserved for all states within the EEZ under UNCLOS.

The concept of the EEZ was established by the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Beyond the EEZ lies the high seas, where all states have equal freedoms. The rights within the EEZ are distinct from the full sovereignty a state exercises over its territorial waters (typically up to 12 nautical miles).

2. Match List-I with List-II and select the correct answer using the code

Match List-I with List-II and select the correct answer using the code given below the Lists :

List-I (Cloud)	List-II (Characteristic)
A. Cirrus	1. Rain-giving
B. Stratus	2. Feathery appearance
C. Nimbus	3. Vertically growing
D. Cumulus	4. Horizontally spreading

Code:

[amp_mcq option1=”A 3, B 1, C 4, D 2″ option2=”A 2, B 1, C 4, D 3″ option3=”A 2, B 4, C 1, D 3″ option4=”A 3, B 4, C 1, D 2″ correct=”option3″]

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UPSC CDS-1 – 2018

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Matching the cloud types with their characteristics:
A. Cirrus: High-altitude clouds composed of ice crystals, appearing thin, wispy, and feathery. Matches characteristic 2 (Feathery appearance).
B. Stratus: Low-altitude, layered clouds that spread horizontally, often covering the entire sky. Matches characteristic 4 (Horizontally spreading).
C. Nimbus: This term denotes a precipitating cloud. Nimbostratus and Cumulonimbus are major rain-giving clouds. Matches characteristic 1 (Rain-giving).
D. Cumulus: Puffy, lumpy clouds that often have flat bases and can grow vertically, sometimes developing into cumulonimbus clouds. Matches characteristic 3 (Vertically growing).
Thus, the correct matching is A-2, B-4, C-1, D-3. This corresponds to option C.

– Cloud classification is based on altitude and appearance.
– Cirrus are high and feathery; Stratus are low and layered; Cumulus are puffy and potentially vertical; Nimbus indicates precipitation.

Clouds are classified into ten main types (genera) based on their appearance and height. These genera are further divided into species and varieties. Understanding the basic characteristics of major cloud types helps in interpreting weather patterns.

3. When the Sun is near the horizon during the morning or evening, it app

When the Sun is near the horizon during the morning or evening, it appears reddish. The phenomenon that is responsible for this observation is

[amp_mcq option1=”reflection of light” option2=”refraction of light” option3=”dispersion of light” option4=”scattering of light” correct=”option4″]

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The phenomenon responsible for the reddish appearance of the Sun near the horizon is scattering of light, specifically Rayleigh scattering. As sunlight passes through a longer path in the Earth’s atmosphere during sunrise or sunset, shorter wavelengths (blue and violet) are scattered away more effectively by air molecules than longer wavelengths (red and orange). The light that reaches the observer’s eyes is therefore enriched in the longer, redder wavelengths.

– Rayleigh scattering is inversely proportional to the fourth power of the wavelength (scattering ∝ 1/λ⁴), meaning shorter wavelengths are scattered much more than longer wavelengths.
– The path length of sunlight through the atmosphere is longest at sunrise and sunset.

Reflection is the bouncing of light off a surface. Refraction is the bending of light as it passes from one medium to another (e.g., causing the sun’s image to appear flattened at the horizon). Dispersion is the splitting of white light into its constituent colors based on wavelength (as in a prism or rainbow). While these phenomena occur, scattering is the primary reason for the reddish appearance of the sun and sky color variations.

4. Two metallic wires made from copper have same length but the radius of

Two metallic wires made from copper have same length but the radius of wire 1 is half of that of wire 2. The resistance of wire 1 is R. If both the wires are joined together in series, the total resistance becomes

[amp_mcq option1=”2R” option2=”R/2″ option3=”5R/4″ option4=”3R/4″ correct=”option3″]

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UPSC CDS-1 – 2018

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The resistance of a wire is given by R = ρ * (l/A), where ρ is the resistivity, l is the length, and A is the cross-sectional area. The area A = πr², where r is the radius.
For wire 1, with radius r1 and length l, the resistance R1 = ρ * l / (πr1²). We are given R1 = R.
For wire 2, with the same length l but radius r2 = 2 * r1 (since r1 is half of r2, r2 is double r1), the resistance R2 = ρ * l / (πr2²) = ρ * l / (π(2r1)²) = ρ * l / (π * 4r1²) = (1/4) * [ρ * l / (πr1²)].
Since R = ρ * l / (πr1²), we have R2 = R/4.
When the two wires are joined in series, the total resistance is the sum of individual resistances: R_total = R1 + R2.
R_total = R + R/4 = 5R/4.

– Resistance is inversely proportional to the square of the radius (R ∝ 1/r²), assuming constant length and material.
– When conductors are in series, their resistances add up (R_total = R1 + R2 + …).

Resistivity (ρ) is a material property. Since both wires are made of copper, they have the same resistivity. The formula for resistance is derived from Ohm’s law and material properties. In series connection, the current is the same through both components, and the total voltage across the combination is the sum of voltage drops across each component.

5. Which of the following represents a relation for ‘heat lost = heat

Which of the following represents a relation for ‘heat lost = heat gained’?

[amp_mcq option1=”Principle of thermal equilibrium” option2=”Principle of colors” option3=”Principle of calorimetry” option4=”Principle of vaporization” correct=”option3″]

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The principle of ‘heat lost = heat gained’ is the fundamental basis of calorimetry. Calorimetry is the science or act of measuring changes in state variables of a body for the purpose of deriving the heat transfer associated with changes of its state due to chemical reactions, physical changes, or phase transitions under specified constraints. In an isolated system, when substances at different temperatures come into contact, heat flows from the hotter substances to the colder substances until thermal equilibrium is reached. The total amount of heat energy lost by the hotter substances equals the total amount of heat energy gained by the colder substances.

The principle of conservation of energy applied to heat transfer between objects in thermal contact is known as the principle of calorimetry.

Thermal equilibrium is the state achieved when objects in contact have reached the same temperature and there is no net heat flow. Vaporization is a phase transition. The principle of colors relates to optics, not heat transfer.

6. Which one of the following elements will be an isobar of calcium if th

Which one of the following elements will be an isobar of calcium if the atomic number of calcium is 20 and its mass number is 40?

[amp_mcq option1=”Element with 20 protons and 18 neutrons” option2=”Element with 18 protons and 19 neutrons” option3=”Element with 20 protons and 19 neutrons” option4=”Element with 18 protons and 22 neutrons” correct=”option4″]

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Isobars are atoms of different elements that have the same mass number (total number of protons and neutrons) but different atomic numbers (number of protons).
Calcium (Ca) has atomic number (Z) = 20 and mass number (A) = 40.
An isobar of Calcium-40 must have a mass number of 40 but an atomic number different from 20.
Let’s examine the options:
A) 20 protons, 18 neutrons: Z=20, A=20+18=38. (Isotope of Ca)
B) 18 protons, 19 neutrons: Z=18 (Argon), A=18+19=37. (Argon-37)
C) 20 protons, 19 neutrons: Z=20, A=20+19=39. (Isotope of Ca)
D) 18 protons, 22 neutrons: Z=18 (Argon), A=18+22=40. (Argon-40). This element has a different atomic number (18) but the same mass number (40) as Calcium-40. Thus, Argon-40 is an isobar of Calcium-40.

Isobars have the same mass number but different atomic numbers.

Isotopes have the same atomic number but different mass numbers. Isotones have the same number of neutrons but different atomic numbers and mass numbers.

7. Which of the following substances cause temporary hardness in water?

Which of the following substances cause temporary hardness in water?

1. Mg(HCO₃)₂
2. Ca(HCO₃)₂
3. CaCl₂
4. MgSO₄

Select the correct answer using the code given below.

[amp_mcq option1=”3 and 4″ option2=”2 and 3″ option3=”1 and 4″ option4=”1 and 2″ correct=”option4″]

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Temporary hardness in water is caused by the presence of dissolved bicarbonates of calcium (Ca(HCO3)2) and magnesium (Mg(HCO3)2). These compounds decompose when water is boiled, forming insoluble calcium carbonate and magnesium carbonate, which precipitate out, thereby removing the hardness.
From the given list:
1. Mg(HCO3)2 – Magnesium bicarbonate (causes temporary hardness)
2. Ca(HCO3)2 – Calcium bicarbonate (causes temporary hardness)
3. CaCl2 – Calcium chloride (causes permanent hardness)
4. MgSO4 – Magnesium sulfate (causes permanent hardness)
Therefore, substances 1 and 2 cause temporary hardness.

Temporary hardness is primarily caused by dissolved calcium and magnesium bicarbonates.

Permanent hardness is caused by dissolved sulfates and chlorides of calcium and magnesium. It cannot be removed by simple boiling but requires other methods like ion exchange or chemical precipitation using agents like washing soda.

8. Which one of the following is not a characteristic of a compound?

Which one of the following is not a characteristic of a compound?

[amp_mcq option1=”Composition is variable.” option2=”All particles of compound are of only one type.” option3=”Particles of compound have two or more elements.” option4=”Its constituents cannot be separated by simple physical methods.” correct=”option1″]

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A compound is a pure substance formed when two or more different elements are chemically bonded together in a fixed ratio. Therefore, the composition of a compound is constant and definite, not variable. Mixtures, on the other hand, have variable compositions.

A defining characteristic of a compound is its fixed and definite composition by mass.

Other characteristics of compounds include that all particles (molecules or formula units) are identical, they contain atoms of two or more elements chemically joined, and their constituent elements lose their individual properties when forming the compound. The elements in a compound can only be separated by chemical means, not simple physical methods.

9. Bright light is found to emit from photographer’s flashgun. This brigh

Bright light is found to emit from photographer’s flashgun. This brightness is due to the presence of which one of the following noble gases?

[amp_mcq option1=”Argon” option2=”Xenon” option3=”Neon” option4=”Helium” correct=”option2″]

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Xenon is the noble gas most commonly used in photographic flashguns and strobe lights. When an electric current is discharged through xenon gas, it produces a brief, intense flash of broadband white light, which is ideal for photography.

Xenon is used in flash lamps due to its ability to produce bright, white light upon electrical discharge.

Other noble gases like Neon are known for their use in signs producing colored light, Argon is used in fluorescent lamps and some discharge lamps, and Helium is used in discharge lamps for specific spectral lines, but none are standard for photographic flashguns like Xenon.

10. Which one of the following places of India experiences highest atmosph

Which one of the following places of India experiences highest atmospheric pressure during winter?

[amp_mcq option1=”Jaisalmer” option2=”Leh” option3=”Chennai” option4=”Guwahati” correct=”option1″]

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Atmospheric pressure is influenced by temperature, altitude, and dynamic weather systems. During winter, strong high-pressure systems develop over the cold continental landmasses, including central Asia and extending into northwest India. While Leh (Ladakh) experiences extreme cold, its very high altitude leads to significantly lower atmospheric pressure compared to locations at lower altitudes. Jaisalmer (Rajasthan) is located in northwest India, which is under the influence of the winter high-pressure system, but at a much lower altitude (~225m) than Leh (~3500m). Chennai and Guwahati are in warmer regions and not under the core influence of the continental winter high. Therefore, among the given options, Jaisalmer is most likely to experience the highest atmospheric pressure during winter due to its location within the winter high-pressure belt at a relatively low altitude compared to Leh.

Winter high pressure systems lead to cold, dense air over landmasses. While cold increases density and thus pressure, altitude significantly reduces pressure. Jaisalmer is located in the region influenced by the winter high at a much lower altitude than Leh.

Actual atmospheric pressure decreases with increasing altitude. A rough estimate is a decrease of about 1 hPa for every 8 meters increase in altitude at lower levels. While Leh’s extreme cold contributes to higher air density, the vast difference in altitude between Leh and Jaisalmer means Jaisalmer’s actual surface pressure will typically be much higher.