SOLVED PAPER 2023 (CDS) (I) (General Studies)

Total Questions: 120

11. Consider the following statements regarding burning of magnesium ribbon in air,

1. White powder of MgO is formed.
2. It is an example of combustion reaction.
3. Heat and light are produced.

Which of the statements given above are correct?

Correct Answer: (d) 1, 2 and 3
Solution:Statements (1), (2) and (3) are correct regarding burning of magnesium ribbon in air.

When magnesium ribbon burns in oxygen, magnesium oxide is formed with the production of dazzling white light. After it burns, the white powder of magnesium oxide gets formed.

The burning of magnesium in air produces intense heat which can cause burns and initiate combustion in flammable materials.

Burning magnesium ribbon in air to form magnesium oxide is an example of combustion and exothermic reaction.

12. Which of the following statements with regard to the reaction given below are correct?

CaO(s) + H₂O(I) →  Ca(OH)₂(aq) + Heat

1. Quicklime is used for white-washing of walls.
2. The solution of slaked lime is used for whitewashing of walls.
3. CaO reacts slowly with CO₂ in air to form a thin layer of CaCO₃ on walls,

4. Calcium hydroxide called 'slaked lime' is an inorganic compound.

Select the correct answer using the codes given below.

Correct Answer: (d) 1, 3 and 4
Solution:Statements (1), (3) and (4) are correct with regard to the given reaction. Quicklime is used for white-washing as it produces calcium hydroxide (CaOH) when it reacts with water (H2O) and absorbs carbon dioxide (CO2) from the environment, as a result, it produces calcium carbonate (CaCO3) which creates a hard coating on the walls.

Calcium hydroxide reacts slowly with the carbon dioxide in the air to form a thin layer of calcium carbonate on the walls. Calcium carbonate is formed after two to three days of white-washing and gives a shiny finish to the walls.

13. Which of the following statement with regard to heating of lead nitrate powder over a flame are correct

1. Brown fumes of NO are released.
2. Colourless O₂ gas is released.
3. It is an example of oxidation reaction.
4. It is an example of thermal decomposition used for the production of NO₂ gas.

Select the correct answer using the codes given below.

Correct Answer: (d) 2 and 4
Solution:Statements (2) and (4) are correct with regard to heating of lead nitrate powder over a flame. When lead nitrate is heated, it breaks down into lead monoxide, nitrogen dioxide, and oxygen.
2 Pb (NO₃) 2 → 2 PbO + 4NO₂ + O₂

Lead nitrate on heating undergo thermal decomposition reaction to form a yellow residue of lead oxide, brown fumes of nitrogen dioxide and oxygen.

14. Which one of the following is not an oxidation reaction?

Correct Answer: (b) Opening of soda bottle
Solution:Opening of soda bottle is not an oxidation reaction. The opening of a soda bottle is neither oxidation nor reduction, but rather a physical process. When a bottle of soda is opened, the pressure inside the bottle is released, causing carbon dioxide gas to escape from the soda. There is no chemical change occurring, as the composition of the soda remains the same.

15. Consider the following clues about a State of India.

1. It is known as 'land of red river and blue hills'.
2 It contains three of the six physiographic divisions of India.
3. It covers about 2.39 percent of total areas of the country.

Identify the State on the basis of the given clues.

Correct Answer: (c) Assam
Solution:Assam State is called as 'land of red river' and blue hills because of its unique topography. Assam is referred because of river Brahmaputra and blue hills that shine at distance forming blue clouds. Assam has physiographic division. Brahmaputra valley, Barak valley and the Karbi-Anglong and the North-Chachar hills.

16. Which of the following sets of states shares boundary with Telangana?

Correct Answer: (d) Chhattisgarh, Andhra Pradesh, Karnataka, Maharashtra
Solution:Telangana is bordered by the state of Maharashtra to the North, Chhattisgarh to the North-East Andhra Pradesh to the South-East and South and Karnataka to the West. Telangana was formed on 2nd June, 2014. Hyderabad made its capital. A committee headed by former Chief Justice B.N Srikrishna studied the formation of Telangana state.

17. Rani told her friends that last year she did boating in four different lakes, namely, Loktak, Barapani, Kolleru and Pulicat. Which of the following States did she visit?

Correct Answer: (b) Manipur, Meghalaya, Andhra Pradesh Tamil Nadu
Solution:Loktak Lake is one of the largest freshwater lake in the world. Located in Manipur. The lake consists of floating grass patches which are like tiny island.

Kolleru Lake is an important wetland of India located in Andhra Pradesh. It is resident for migratory birds.

Pulicat Lake is located in Tamil Nadu. It is the second largest brackish water lake in India after Chillika lake.

Barapani Lake is located in Meghalaya. It is also known as Umiam lake. It is formed by Umiam river after the construction of Dam on it. It is a reservoir.

18. According to the Census 2011, which of the following statements is/are correct?

1. A person who can only read but cannot write, is not literate.
2. A person aged seven years and above, who can both read and write with understanding in any language is treated as literate.

Select the correct answer using the codes given below.

Correct Answer: (c) Both 1 and 2
Solution:Both (1) and (2) are correct. According to Census 2011, literate is a person who acquires the capacities of reading and writing by himself or herself. According to Census 2001, a literate person is one who is 7 year old and can read and write any language with understanding.

India's total literacy rate is 77.70%. At the time of Independence it was only 18%.

19. The Tropic of Cancer passes through how many coastal and landlocked States of India, respectively?

Correct Answer: (b) 2 and 6
Solution:The Tropic of Cancer passes through 8 states in India. Gujarat, Rajasthan, Madhya Pradesh Chhattisgarh Jharkhand, West Bengal, Tripura and Mizoram. The tropic of cancer marks the most northerly latitude at which the sun can appear directly overhead at noon. The Tropic of Cancer also referred as the Northern tropic. It passes through 2 coastal states Gujarat and West Bengal and 8 land locked states.

20. Which one of the following situations can lead to inflation?

Correct Answer: (a) Rapid growth of aggregate demand outweighing supply.
Solution:Rapid growth of aggregate demand out weigh supply lead to inflation.

Demand-pull inflation refers to situation where there are not enough products or services being produced to keep up with demand, causing their prices to increase cost-push inflation. On the other hand, cost push inflation occurs when the cost of producing products and services rises, forcing business to rise their prices.

When this happens across a large number of businesses and sectors, this leads to an increase in inflation.