UPSC CDS-1 Archives

1. Methyl Isocyanate gas, which was involved in the disaster in Bhopal in

Methyl Isocyanate gas, which was involved in the disaster in Bhopal in December 1984, was used in the Union Carbide factory for production of :

Dyes

Detergents

Explosives

Pesticides

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

Methyl Isocyanate (MIC) gas involved in the Bhopal disaster was used in the production of pesticides.

The Union Carbide India Limited (UCIL) plant in Bhopal produced the pesticide Carbaryl, marketed under the brand name Sevin. Methyl Isocyanate (MIC) was a key intermediate chemical used in the synthesis of Carbaryl. The disaster occurred due to a leak of MIC gas from the plant.

Carbaryl is a carbamate insecticide used to control insect pests on crops. The Bhopal gas tragedy is one of the world’s worst industrial disasters.

2. Which of the following statements regarding Mediterranean and Monsoon

Which of the following statements regarding Mediterranean and Monsoon climate is / are correct ?

1. Precipitation in Mediterranean climate is in winter while in Monsoon climate it is mostly in summer
2. The annual range of temperature in Mediterranean climate is higher than the Monsoon climate
3. Rainy and dry seasons are found in both the climates

Select the correct answer using the code given below:

1 only

2 and 3 only

1 and 3 only

1, 2 and 3

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

Statements 1 and 3 are correct. Statement 2 is generally incorrect.

Statement 1 accurately describes the seasonal distribution of precipitation in Mediterranean (winter) and Monsoon (mostly summer) climates. Statement 3 correctly notes the presence of distinct rainy and dry seasons in both climate types, although the timing differs. Statement 2 is not a reliable generalization; while the annual temperature range can vary within both climate types depending on location (coastal vs. continental), Mediterranean coastal areas often have a lower annual range compared to many continental monsoon regions due to the moderating influence of the sea.

Mediterranean climate is characterized by hot, dry summers and mild, wet winters. Monsoon climate, particularly the tropical monsoon, is characterized by heavy rainfall in the summer months following a dry period, and a relatively dry winter. Both climates exhibit seasonality in precipitation, but the wet season occurs at opposite times of the year relative to summer.

3. Consider the following statements regarding laterite soils of India :

Consider the following statements regarding laterite soils of India :

1. Laterite soils are generally red in colour
2. Laterite soils are rich in nitrogen and potash
3. Laterite soils are well developed in Rajasthan and UP
4. Tapioca and cashew nuts grow well in this soil

Which of the statements given above is / are correct?

1 only

2, 3 and 4

1 and 4 only

1, 2 and 4

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is C) 1 and 4 only.

Let’s evaluate each statement about laterite soils:
1. Laterite soils are generally red in colour: Correct. They are reddish-brown due to the presence of iron oxides.
2. Laterite soils are rich in nitrogen and potash: Incorrect. Laterite soils are typically poor in nitrogen, potash, phosphorus, lime, and organic matter due to intense leaching of bases in areas with high rainfall and high temperatures. They are rich in iron and aluminium oxides.
3. Laterite soils are well developed in Rajasthan and UP: Incorrect. Laterite soils are primarily found in areas with high rainfall and alternating wet and dry periods, which promote leaching. They are well developed in the Western Ghats, Eastern Ghats, parts of Odisha, West Bengal, Karnataka, Kerala, Assam, and Meghalaya. Rajasthan and UP are generally not areas where laterite soils are widespread.
4. Tapioca and cashew nuts grow well in this soil: Correct. Despite being infertile for most crops due to leaching, laterite soils, with proper management like irrigation and fertilization, are suitable for specific crops such as cashew nuts, tapioca, coffee, tea, and rubber.

Laterite soils are residual soils formed by intense leaching (laterization) under specific climatic conditions. They harden irreversibly when exposed to air, making them useful as building material (laterite bricks). Their low fertility is a major challenge for agriculture, requiring specific cultivation practices and crop selection.

4. Pir Panjal Range in the Himalayas is a part of :

Pir Panjal Range in the Himalayas is a part of :

Shiwalik

Trans Himalaya

Central Himalaya

Lesser Himalaya

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is D) Lesser Himalaya.

The Himalayan mountain range is geographically divided into several parallel ranges running broadly from west to east. From north to south, these major ranges are the Trans-Himalaya, Great Himalayas (Himadri), Lesser Himalayas (Himachal), and Outer Himalayas (Shiwaliks). The Pir Panjal Range is the largest range of the Lesser Himalayas, located in the Indian state of Jammu and Kashmir and Himachal Pradesh.

The Lesser Himalayas have an average elevation ranging from 3,700 to 4,500 meters. Besides Pir Panjal, other important ranges within the Lesser Himalayas include the Dhaula Dhar, Mussoorie, and Nag Tiba ranges. These ranges are characterized by their rugged terrain, beautiful valleys (like Kashmir Valley, Kangra Valley), and popular hill stations.

5. Consider the following map of India : The areas marked in the map give

Consider the following map of India :
The areas marked in the map given above account for the production of which one of the following cash crops ?

Cotton

Groundnut

Sugarcane

Tobacco

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

Assuming the map marks the areas of the Deccan Plateau and surrounding regions (like parts of Maharashtra, Gujarat, Madhya Pradesh, Karnataka, and Andhra Pradesh), the primary cash crop these areas account for in significant production is Cotton.

Without the actual map, this answer is based on the common geographical distribution of major cash crops in India and typical representations in such exam questions. The black soil region of the Deccan Plateau is particularly well-suited for cotton cultivation due to its moisture-retaining capacity and nutrients. Gujarat and Maharashtra are among the leading cotton-producing states in India.

Sugarcane production is dominated by Uttar Pradesh, followed by Maharashtra and Karnataka. Groundnut production is significant in Gujarat, Rajasthan, Tamil Nadu, Andhra Pradesh, and Karnataka, often in semi-arid areas. Tobacco production is more scattered, with major areas including Andhra Pradesh and Gujarat. Given the context of a single cash crop being represented by marked areas, cotton cultivation areas are a strong possibility for regions covering parts of Western and Central India as well as parts of the South.

6. After a hot sunny day, people sprinkle water on the roof-top because :

After a hot sunny day, people sprinkle water on the roof-top because :

water helps air around the roof-top to absorb the heat instantly

water has lower specific heat capacity

water is easily available

water has large latent heat of vaporisation

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is D) water has large latent heat of vaporisation.

When water is sprinkled on a hot surface like a rooftop, it evaporates. Evaporation is a process that requires energy (heat). This energy is absorbed from the surroundings, including the rooftop itself and the air, as the water changes from liquid to gas phase. The latent heat of vaporisation is the amount of heat energy required to change a substance from a liquid to a gas at a constant temperature. Water has a relatively high latent heat of vaporisation, meaning it absorbs a significant amount of heat from the rooftop during evaporation, leading to a substantial cooling effect.

Other options are less accurate or irrelevant. While water absorbs heat, the primary cooling mechanism here is the energy required for the phase change (latent heat), not simple heat absorption in liquid form (specific heat capacity). A higher specific heat capacity means it takes more energy to raise the temperature of water, which is also a factor in moderating temperature, but the cooling on a hot day is mainly due to the heat removed during evaporation. Water availability is a practical reason for using it, not the scientific principle behind the cooling.

7. The rate of change of momentum of a body is equal to the resultant :

The rate of change of momentum of a body is equal to the resultant :

energy

power

force

impulse

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is C) force.

According to Newton’s Second Law of Motion, the rate of change of momentum of a body is directly proportional to the net force applied to it and occurs in the direction of the applied force. Mathematically, this is expressed as F = dp/dt, where F is the net force, p is the momentum, and t is time.
Momentum (p) is defined as the product of mass (m) and velocity (v), i.e., p = mv.
If mass is constant, the rate of change of momentum is d(mv)/dt = m(dv/dt) = ma, where a is acceleration. This is the more commonly known form of Newton’s Second Law, F = ma.

Energy is related to work and the capacity to do work. Power is the rate at which work is done or energy is transferred. Impulse is the change in momentum, calculated as the product of force and the time interval over which it acts (Impulse = F * Δt = Δp). The question specifically asks for the *rate* of change of momentum, which is defined as force.

8. Which of the following pairs of vitamin and disease is / are correctly

Which of the following pairs of vitamin and disease is / are correctly matched ?

1. Vitamin A : Rickets
2. Vitamin B₁ : Beriberi
3. Vitamin C : Scurvy

Select the correct answer using the code given below :

2 only

2 and 3 only

1 and 3 only

1, 2 and 3

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is B) 2 and 3 only.

Let’s evaluate each statement:
1. Vitamin A : Rickets. Rickets is caused by Vitamin D deficiency, leading to weakened and deformed bones, primarily in children. Vitamin A deficiency causes xerophthalmia (including night blindness) and increased susceptibility to infections. So, statement 1 is incorrect.
2. Vitamin B₁ : Beriberi. Beriberi is a disease caused by a deficiency of thiamine (Vitamin B₁), affecting the nervous system, cardiovascular system, and gastrointestinal system. Symptoms include weakness, nerve damage, and heart problems. So, statement 2 is correct.
3. Vitamin C : Scurvy. Scurvy is a disease caused by a deficiency of ascorbic acid (Vitamin C). It leads to symptoms like fatigue, bleeding gums, joint pain, skin lesions, and poor wound healing. So, statement 3 is correct.

Deficiencies of essential vitamins lead to specific deficiency diseases. Understanding the links between vitamins and their associated deficiency diseases is important for health and nutrition. Other notable examples include Pellagra (Niacin/B₃ deficiency), Pernicious Anemia (Vitamin B₁₂ deficiency), and Goiter (Iodine deficiency, a mineral, not a vitamin).

9. Which one of the following is considered as ‘good cholesterol’ with re

Which one of the following is considered as ‘good cholesterol’ with reference to individuals facing the risk of cardio-vascular diseases and hypertension ?

High Density Lipoprotein (HDL)

Low Density Lipoprotein (LDL)

Triglyceride

Fatty acids

This question was previously asked in

UPSC CDS-1 – 2016

Download PDF Attempt Online

The correct option is A) High Density Lipoprotein (HDL).

Lipoproteins are particles that transport cholesterol and other fats in the blood. HDL (High Density Lipoprotein) is often referred to as ‘good cholesterol’ because it helps remove excess cholesterol from arteries and transport it back to the liver, where it can be processed and removed from the body. This action helps prevent the buildup of plaque in arteries, reducing the risk of cardiovascular diseases.

LDL (Low Density Lipoprotein) is considered ‘bad cholesterol’ because it contributes to the buildup of plaque in the arteries. High levels of LDL increase the risk of heart disease and stroke. Triglycerides are another type of fat in the blood; high levels are also linked to increased risk of heart disease. Maintaining a healthy balance between HDL and LDL is important for cardiovascular health.

10. Which one of the following tissues is responsible for increase of girt

Which one of the following tissues is responsible for increase of girth in the stem of a plant?

Tracheid

Pericycle

Intercalary meristem

Lateral meristem

This question was previously asked in

UPSC CDS-1 – 2019

Download PDF Attempt Online

Lateral meristems are responsible for secondary growth, which is the increase in the diameter or girth of stems and roots. The two main types of lateral meristems are the vascular cambium (producing secondary xylem and phloem) and the cork cambium (producing the periderm, including cork).

Lateral meristems cause growth in girth (secondary growth) in plants.

Tracheids are components of xylem tissue involved in water transport and support. Pericycle is a layer of cells in the root from which lateral roots arise and sometimes contributes to secondary growth. Intercalary meristems are located at nodes in monocots and are responsible for increases in stem length between nodes (primary growth).