UPSC CDS-1

31. Consider the following chemical reaction : aFe₂O₃(s) + bCO(g) → cFe(s)

Consider the following chemical reaction :
aFe₂O₃(s) + bCO(g) → cFe(s) + dCO₂
In the balanced chemical equation of the above, which of the following will be the values of the coefficients a, b, c and d respectively?

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3, 2, 3, 1
1, 3, 2, 3
2, 3, 3, 1
3, 3, 2, 1
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The given chemical reaction is the reduction of iron(III) oxide by carbon monoxide: Fe₂O₃(s) + CO(g) → Fe(s) + CO₂(g). To balance the equation aFe₂O₃ + bCO → cFe + dCO₂, we balance the atoms of each element:
– Fe: 2a = c
– O: 3a + b = 2d
– C: b = d
Substituting b=d into the oxygen balance: 3a + d = 2d, which gives 3a = d.
So we have the relationships: c = 2a, b = 3a, d = 3a.
To find the smallest integer coefficients, we can set a=1.
Then, b = 3(1) = 3, c = 2(1) = 2, d = 3(1) = 3.
The coefficients are a=1, b=3, c=2, d=3. This corresponds to option B.
– Balancing chemical equations involves ensuring the number of atoms of each element is the same on both the reactant and product sides.
– Coefficients represent the relative number of molecules or moles involved in the reaction.
– Balancing is achieved by using stoichiometric coefficients in front of the chemical formulas.
This reaction is a key process in the blast furnace for smelting iron ore, where iron(III) oxide is reduced by carbon monoxide produced from the combustion of coke. The balanced equation shows that one molecule of iron(III) oxide reacts with three molecules of carbon monoxide to produce two atoms of iron and three molecules of carbon dioxide.

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32. Which one of the following elements is essential for the formation of

Which one of the following elements is essential for the formation of chlorophyll in green plants?

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Calcium
Iron
Magnesium
Potassium
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Magnesium (Mg) is an essential element for the formation of chlorophyll. Each chlorophyll molecule contains a magnesium atom at the center of a porphyrin ring structure.
– Chlorophyll is the primary pigment responsible for absorbing light energy during photosynthesis.
– Its unique structure, with a central magnesium atom, is crucial for its function in capturing light.
– Deficiency of magnesium in plants leads to chlorosis, a yellowing of leaves, particularly between the veins, due to reduced chlorophyll production.
Calcium is important for cell wall structure and signaling. Iron is essential for enzyme activity in chlorophyll synthesis and electron transport, but it is not a structural component of chlorophyll itself. Potassium is important for osmoregulation, enzyme activation, and stomatal control. While all these elements are vital for plant health and growth, Magnesium is the specific element that is a constituent part of the chlorophyll molecule.

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33. Which one of the following gases dissolves in water to give acidic

Which one of the following gases dissolves in water to give acidic solution?

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Carbon dioxide
Oxygen
Nitrogen
Hydrogen
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Carbon dioxide (CO₂) dissolves in water to form carbonic acid (H₂CO₃). Carbonic acid is a weak acid that partially dissociates into hydrogen ions (H⁺) and bicarbonate ions (HCO₃⁻), thus lowering the pH and making the solution acidic. The reaction is CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻.
– An acidic solution is formed when a substance dissolves in water and increases the concentration of hydrogen ions (H⁺) or hydronium ions (H₃O⁺).
– Non-metal oxides, like carbon dioxide, often react with water to form acids.
– Oxygen, Nitrogen, and Hydrogen are non-polar or weakly polar molecules that dissolve in water but do not react chemically to produce acidic or basic solutions; they remain neutral.
The acidity of solutions of gases like CO₂ is important in various natural processes, such as the formation of acid rain (from oxides of sulfur and nitrogen) and the buffering system in blood involving carbonic acid and bicarbonate. The dissolution of CO₂ in oceans leads to ocean acidification.

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34. Which one of the following elements is involved in the control of wate

Which one of the following elements is involved in the control of water content of the blood?

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Potassium
Lithium
Rubidium
Caesium
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Potassium is the correct answer among the given options. While sodium is the primary electrolyte determining the osmotic pressure of extracellular fluid, including blood plasma, and thus the control of water content, potassium is the major intracellular cation and plays a critical role in maintaining cell volume and membrane potential. Proper balance of potassium is essential for the function of the kidneys, which regulate water and electrolyte excretion, thereby influencing blood volume and water content. Hormones like aldosterone regulate both sodium and potassium levels, highlighting their interconnected roles in fluid homeostasis.
– Water content of blood is controlled by the balance of electrolytes, primarily sodium in the extracellular fluid.
– Potassium is a crucial intracellular electrolyte involved in cell volume and membrane function.
– The kidneys, regulated by hormones, control electrolyte and water balance.
– Among the options provided, Potassium is the only major electrolyte with a significant role in overall fluid and electrolyte balance impacting blood water content, especially through its influence on kidney function and cellular osmotic balance.
Sodium (Na⁺) is the main electrolyte responsible for the osmotic pressure of extracellular fluid. Hormones like ADH (Antidiuretic Hormone) and Aldosterone regulate water and sodium reabsorption/excretion by the kidneys, directly influencing blood volume and water content. While potassium’s role in blood water content control is less direct than sodium’s, its proper balance is essential for normal physiological function, including kidney function and cellular integrity, which are critical for maintaining overall fluid homeostasis. Lithium has medicinal uses but is not a primary regulator of normal fluid balance; Rubidium and Caesium are not essential electrolytes and can be toxic.

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35. Which one of the following elements is used as a timekeeper in atomic

Which one of the following elements is used as a timekeeper in atomic clocks?

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Potassium
Caesium
Calcium
Magnesium
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Atomic clocks utilize the precise frequency of electromagnetic radiation absorbed or emitted by atoms during an electron transition between energy levels. Caesium-133 atoms are most commonly used as the primary standard for defining the second in modern atomic clocks. The official SI definition of the second is based on the frequency of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the Caesium-133 atom.
Caesium-133 is the standard element used as a timekeeper in traditional atomic clocks due to the stable and precisely known frequency of its atomic transition.
While Caesium clocks are the most widespread standard, other elements like Rubidium are also used, and advanced research is ongoing using elements like Strontium and Ytterbium in optical lattice clocks which offer even higher precision.

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36. Which one of the following constitutional authorities inquires and dec

Which one of the following constitutional authorities inquires and decides in case of doubts and disputes arising out of election of the President and Vice President of India?

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The Supreme Court of India
The Election Commission of India
The Parliamentary Committee
The High Court of Delhi
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Article 71(1) of the Constitution of India explicitly states that all doubts and disputes arising out of or in connection with the election of a President or Vice-President shall be inquired into and decided by the Supreme Court. The decision of the Supreme Court in such matters is final.
The Supreme Court of India is the sole constitutional authority empowered to inquire into and decide doubts and disputes regarding the election of the President and Vice President.
The Election Commission of India is responsible for conducting the elections to the offices of President and Vice President, but it does not have the power to resolve election disputes or challenges. Such matters must be filed as an election petition directly before the Supreme Court.

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37. Which one of the following statements is not correct regarding the Off

Which one of the following statements is not correct regarding the Office of the Vice President of India?

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The Vice President is elected by an electoral college consisting of the elected members of both the Houses of the Parliament.
The Vice President is elected in accordance with the system of proportional representation by means of single transferable vote.
The Vice President shall not be a member of either House of the Parliament or of a House of the Legislature of any State.
The Vice President of India shall be ex officio Chairman of the Council of States and shall not hold any office of profit.
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The election of the Vice President of India is governed by Article 66 of the Constitution.
Statement A: Article 66(1) states that the Vice President shall be elected by the members of an electoral college consisting of the members of both Houses of Parliament in accordance with the system of proportional representation by means of the single transferable vote. The electoral college for the Vice President consists of *all* members of both the Houses of Parliament (elected and nominated), not just the elected members. Therefore, this statement is incorrect.
Statement B: Article 66(1) specifies the method of election as proportional representation by means of single transferable vote. This is correct.
Statement C: Article 66(2) states that the Vice President shall not be a member of either House of Parliament or of a House of the Legislature of any State, and if elected while being a member, shall be deemed to have vacated the seat. This is correct.
Statement D: Article 64 states that the Vice President shall be ex officio Chairman of the Council of States (Rajya Sabha) and shall not hold any other office of profit. This is correct.
Therefore, statement A is the one that is not correct.
The electoral college for the Vice President comprises all members (elected and nominated) of both the Rajya Sabha and the Lok Sabha, unlike the President’s electoral college which includes only elected members of Parliament and State Legislative Assemblies.
The Vice President serves as the Chairman of the Rajya Sabha. In the event of a vacancy in the office of President or the President being unable to discharge his functions, the Vice President acts as President.

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38. Which one of the following statements relating to the Directive Princi

Which one of the following statements relating to the Directive Principles of State Policy is not correct?

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The provisions contained in Part IV of the Constitution of India shall not be enforceable by any Court.
The Directive Principles of State Policy are fundamental in the governance of the country.
It shall be the duty of the State to apply the Directive Principles in making laws.
The Directive Principles are directed in making India an advanced capitalist country of the world.
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The Directive Principles of State Policy (DPSPs), contained in Part IV of the Indian Constitution (Articles 36-51), lay down certain goals that the State should strive to achieve for the welfare of the people.
Statement A: Article 37 explicitly states that the provisions contained in Part IV shall not be enforceable by any court. This is correct.
Statement B: Article 37 also states that the principles therein laid down are nevertheless fundamental in the governance of the country. This is correct.
Statement C: Article 37 further states that it shall be the duty of the State to apply these principles in making laws. This is correct.
Statement D: The DPSPs are aimed at creating a welfare state and establishing social and economic democracy. They include principles related to social justice, economic equality, rights of workers, protection of environment, international peace, etc. They are not directed towards making India an advanced capitalist country. Capitalism is an economic system often contrasted with the principles of a welfare state promoted by DPSPs. This statement is incorrect.
Therefore, statement D is the one that is not correct.
DPSPs aim to establish a welfare state and achieve social and economic democracy, guiding the State towards achieving these ideals, rather than promoting capitalism as the primary goal.
DPSPs are non-justiciable, meaning they cannot be enforced by courts, but they are fundamental in the country’s governance and are meant to guide the executive and legislature. They represent the social and economic conscience of the Constitution.

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39. Which one of the following statements relating to cultural and educati

Which one of the following statements relating to cultural and educational rights in India is not correct?

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Every section of the citizens has the right to conserve its language, script or culture.
No citizen shall be denied admission into any educational institution maintained by the State or receiving aid out of State funds on grounds of religion, race or language.
The State shall, in granting aid to educational institutions, discriminate against any educational institution on the ground that it is under the management of a majority community.
All minorities, whether based on religion or language, shall have the right to establish and administer educational institutions of their choice.
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Cultural and Educational Rights are primarily covered by Articles 29 and 30 of the Indian Constitution.
Statement A: Article 29(1) guarantees the right of any section of citizens with a distinct language, script, or culture to conserve the same. This is correct.
Statement B: Article 29(2) prohibits discrimination in admission to educational institutions maintained by the State or receiving State aid on grounds of religion, race, caste, or language. This is correct.
Statement C: Article 30(2) states that the State shall not, in granting aid to educational institutions, discriminate against any educational institution on the ground that it is under the management of a *minority*, whether based on religion or language. The statement says the state will discriminate against institutions under the management of a *majority* community, which is the opposite of the constitutional provision. The Constitution protects minorities from such discrimination in aid, it does not endorse discrimination against the majority or against minorities in favour of the majority in this context. This statement is incorrect.
Statement D: Article 30(1) grants all minorities, religious or linguistic, the right to establish and administer educational institutions of their choice. This is correct.
Therefore, statement C is the one that is not correct.
Article 30(2) prohibits the state from discriminating against minority-managed educational institutions when granting aid. Statement C incorrectly applies this principle to majority communities and reverses the concept of non-discrimination.
Articles 29 and 30 are part of the Fundamental Rights in Part III of the Constitution. Article 29 protects the interests of minorities (and any section of citizens) by allowing them to conserve their distinct language, script, or culture and prohibiting discrimination in state-funded educational institutions. Article 30 specifically guarantees minorities the right to establish and administer their own educational institutions.

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40. Directions: The following two (2) items consist of two statements, Sta

Directions:
The following two (2) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the correct answer using the code given below.
111. Statement I :
The passing of the Coercive Acts made reconciliation between Britain and her American colonies virtually impossible.
Statement II :
The British Parliament, having issued the Stamp Act in 1765, repealed it later.
Code :

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Both the statements are individually true and Statement II is the correct explanation of Statement I
Both the statements are individually true but Statement II is not the correct explanation of Statement I
Statement I is true but Statement II is false
Statement I is false but Statement II is true
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Statement I asserts that the Coercive Acts made reconciliation between Britain and its American colonies virtually impossible. The Coercive Acts (1774), seen as punishment for the Boston Tea Party, closed the port of Boston, altered the Massachusetts charter, and restricted town meetings, among other punitive measures. These acts were perceived as a major assault on colonial liberties and significantly escalated tensions, pushing the colonies closer to rebellion. Thus, Statement I is true. Statement II states that the British Parliament, having issued the Stamp Act in 1765, repealed it later. The Stamp Act was indeed passed in 1765 and repealed in 1766 due to colonial resistance. This statement is also true. However, the repeal of the Stamp Act in 1766 was an earlier event that temporarily eased tensions, while the Coercive Acts of 1774 reignited and intensified conflict. The repeal of the Stamp Act does not explain why the Coercive Acts made reconciliation impossible; in fact, the failure of such attempts at reconciliation (like the Stamp Act repeal) arguably highlighted the widening gap that later acts like the Coercive Acts exploited. Therefore, both statements are individually true, but Statement II is not the correct explanation of Statement I.
Statement I accurately describes the impact of the Coercive Acts on Anglo-American relations. Statement II accurately describes the passage and repeal of the Stamp Act. The repeal of the Stamp Act (1766) is historically separate from and does not explain the impact of the Coercive Acts (1774).
The Coercive Acts were followed by the First Continental Congress in 1774, where colonial delegates met to coordinate a response, further cementing opposition to British rule. The repeal of the Stamp Act in 1766 was accompanied by the Declaratory Act, asserting Parliament’s authority to legislate for the colonies “in all cases whatsoever,” which foreshadowed future conflicts.

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