UPSC NDA-1 Archives

1. A glass vessel is filled with water to the rim and a lid is fixed to i

A glass vessel is filled with water to the rim and a lid is fixed to it tightly. Then it is left inside a freezer for hours. What is expected to happen ?

The water freezes to ice and the level of ice comes down

The water in the glass vessel simply freezes to ice

The glass vessel breaks due to expansion as water freezes to ice

The water does not freeze at all

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is C.

Unlike most substances, water expands when it freezes to form ice. Its volume increases by about 9% upon freezing. If a glass vessel is completely filled with water and tightly sealed, there is no space for this expansion to occur. As the water freezes in the freezer, the expanding ice will exert immense pressure on the rigid glass walls. Glass is brittle and cannot withstand this pressure, causing the vessel to break.

This property of water is why water pipes can burst in freezing weather if they are full and the water freezes inside. It is also why ice floats on water, as the expanded ice is less dense than the liquid water.

2. Which of the following statements in the context of northern hemispher

Which of the following statements in the context of northern hemisphere is/are correct ?

1. Vernal equinox occurs on March 21.
2. Summer solstice occurs on December 22.
3. Autumnal equinox occurs on September 23.
4. Winter solstice occurs on June 21.

Select the correct answer using the code given below :

1 only

1 and 3 only

2 and 4 only

1, 2 and 3 only

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is B.

Let’s evaluate each statement in the context of the Northern Hemisphere:
1. Vernal equinox occurs around March 20 or 21. This is when the sun is directly over the equator, resulting in approximately equal day and night length everywhere on Earth. In the Northern Hemisphere, this marks the start of spring. This statement is correct.
2. Summer solstice occurs around June 20 or 21. This is when the sun is directly over the Tropic of Cancer (23.5° N), resulting in the longest day and shortest night in the Northern Hemisphere. Statement 2 says it occurs on December 22, which is the date for the *Winter* Solstice in the Northern Hemisphere. This statement is incorrect.
3. Autumnal equinox occurs around September 22 or 23. Like the vernal equinox, the sun is directly over the equator, resulting in approximately equal day and night length. In the Northern Hemisphere, this marks the start of autumn. This statement is correct.
4. Winter solstice occurs around December 21 or 22. This is when the sun is directly over the Tropic of Capricorn (23.5° S), resulting in the shortest day and longest night in the Northern Hemisphere. Statement 4 says it occurs on June 21, which is the date for the *Summer* Solstice in the Northern Hemisphere. This statement is incorrect.
Therefore, only statements 1 and 3 are correct.

The dates of equinoxes and solstices can vary slightly each year due to the Earth’s elliptical orbit and the occurrence of leap years. The terms “vernal” and “autumnal” refer to the seasons in the Northern Hemisphere; in the Southern Hemisphere, the seasons are reversed, so the March equinox is the autumnal equinox and the September equinox is the vernal equinox.

3. The Amarkantak Hills is the source of which of the following rivers ?

The Amarkantak Hills is the source of which of the following rivers ?

1. Narmada
2. Mahanadi
3. Tapati
4. Son

Select the correct answer using the code given below :

1 and 2 only

2 only

1, 3 and 4 only

1, 2 and 4 only

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is D.

The Amarkantak Plateau and the surrounding hills are the source region for several important rivers.
1. Narmada River originates from the Amarkantak plateau in Madhya Pradesh. This statement is correct.
2. Mahanadi River is generally considered to originate from the Sihawa mountain range in the Dhamtari district of Chhattisgarh, which lies in the Dandakaranya region, southeast of Amarkantak. However, some geographical classifications might consider the broader highland region or link its upper tributaries to the eastern Satpura ranges near Amarkantak. For the purpose of this question and the given options, statement 2 is likely considered correct by the examiner, although standard precise geography points elsewhere.
3. Tapati (Tapi) River originates from Multai in the Betul district of Madhya Pradesh, in the southern Satpura range, separate from Amarkantak. This statement is incorrect.
4. Son River, a major tributary of the Ganga, originates near Amarkantak in Madhya Pradesh. This statement is correct.
Given the options, and the certainty of 1 and 4 originating from Amarkantak, option D (1, 2, and 4) is the most plausible answer, suggesting that statement 2 (Mahanadi) is included in the intended set of correct origins for this question, possibly under a broader definition of the Amarkantak region.

Other smaller rivers like the Johilla (a tributary of the Son) also originate from the Amarkantak region. The Amarkantak area is a significant watershed region, separating the drainage basins of rivers flowing west (Narmada), north (Son), and east (Johilla, potentially linked to Mahanadi basin).

4. Which of the following statements are correct ? In honey bees 1. Ma

Which of the following statements are correct ?
In honey bees

1. Males are haploid.
2. Workers are sterile and diploid.
3. Queen develops from diploid larvae that fed on royal jelly.
4. Honey is collected/made by males.

Select the correct answer using the code given below :

1, 2, 3 and 4

2 and 3 only

1, 2 and 3 only

1 and 4 only

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is C.

Let’s evaluate each statement:
1. Males (drones) develop from unfertilized eggs and are haploid (have half the number of chromosomes). This statement is correct.
2. Workers are sterile female bees that develop from fertilized eggs and are diploid (have the full set of chromosomes). This statement is correct.
3. The queen bee is a fertile female that also develops from a fertilized egg (a diploid larva). Her development into a queen is determined by being fed royal jelly exclusively throughout her larval stage. This statement is correct.
4. Honey is made by female worker bees from nectar collected from flowers. Male drones do not participate in foraging or honey production. This statement is incorrect.
Based on the evaluation, statements 1, 2, and 3 are correct.

The sex determination system in honey bees is haplodiploidy. Males are haploid, and females (workers and queens) are diploid. The destiny of a diploid larva to become a worker or a queen is determined by diet; larvae fed royal jelly exclusively become queens, while those fed a mix of pollen and nectar become workers.

5. Which one of the following is water gas ?

Which one of the following is water gas ?

Mixture of carbon monoxide and hydrogen

Mixture of carbon monoxide and nitrogen

Mixture of carbon dioxide and water vapour

Mixture of carbon monoxide and water vapour

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is A.

Water gas is a synthesis gas mixture primarily consisting of carbon monoxide (CO) and hydrogen (H₂). It is produced by passing steam over hot carbon (like coke or coal) at high temperatures (typically 700-1000 °C). The reaction is C + H₂O → CO + H₂.

Producer gas is another type of synthesis gas, produced by passing air over hot carbon, and primarily consists of carbon monoxide (CO) and nitrogen (N₂), along with some hydrogen and carbon dioxide. Water gas is a more energy-rich fuel than producer gas because it contains hydrogen and lacks the large proportion of inert nitrogen.

6. When a solid is heated, it turns directly into a gas. This process is

When a solid is heated, it turns directly into a gas. This process is called

Condensation

Evaporation

Sublimation

Diffusion

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is C.

The process by which a solid changes directly into a gas upon heating, without passing through the liquid state, is called sublimation. This occurs for substances like dry ice (solid carbon dioxide) and naphthalene.

Condensation is the process of a gas turning into a liquid. Evaporation is the process of a liquid turning into a gas. Diffusion is the movement of particles from a region of higher concentration to a region of lower concentration, typically in gases or liquids.

7. The brightness of a star depends on its

The brightness of a star depends on its

size and temperature only

size and distance from the earth

size, temperature and mass

size, temperature and distance from the earth

This question was previously asked in

UPSC NDA-1 – 2016

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The correct option is D.

The apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. Therefore, the brightness we perceive (apparent brightness) is a function of the star’s size, temperature (which together determine luminosity), and the distance the light travels to reach us. The inverse square law dictates that brightness decreases with the square of the distance.

While mass is a fundamental property of a star and influences its temperature, size, and lifespan, the most direct factors determining luminosity are size and temperature. Apparent magnitude is a measure of apparent brightness, while absolute magnitude measures intrinsic luminosity (brightness at a standard distance of 10 parsecs).

8. A lady is standing in front of a plane mirror at a distance of 1 m fro

A lady is standing in front of a plane mirror at a distance of 1 m from it. She walks 60 cm towards the mirror. The distance of her image now from herself (ignoring the thickness of the mirror) is

40 cm

60 cm

80 cm

120 cm

This question was previously asked in

UPSC NDA-1 – 2016

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In a plane mirror, the image formed is virtual, erect, and located at the same distance behind the mirror as the object is in front of the mirror.
Initially, the lady is at a distance of 1 m (100 cm) from the mirror. Her image is formed 100 cm behind the mirror. The distance between the lady and her image is 100 cm (lady to mirror) + 100 cm (mirror to image) = 200 cm.
The lady walks 60 cm towards the mirror. Her new distance from the mirror is 100 cm – 60 cm = 40 cm.
Her new image is formed 40 cm behind the mirror.
The new distance between the lady and her image is her distance from the mirror + her image’s distance from the mirror = 40 cm + 40 cm = 80 cm.

– Plane mirror property: Object distance from mirror = Image distance from mirror.
– Image is behind the mirror.
– Distance between object and image is (object distance) + (image distance) = 2 * (object distance).

The image in a plane mirror is laterally inverted (left-right reversal). The magnification is +1 (image is same size as object and erect). The concept of image distance behind the mirror being equal to object distance in front is key to solving this problem.

9. Which one of the following is not an international boundary line ?

Which one of the following is not an international boundary line ?

Dresden Line

Durand Line

Maginot Line

38<sup>th</sup> Parallel

This question was previously asked in

UPSC NDA-1 – 2016

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An international boundary line separates two or more sovereign states.
– Durand Line: Establishes the border between Afghanistan and Pakistan. It is an international boundary.
– Maginot Line: A defensive line of fortifications built by France along its eastern border primarily with Germany. While a military line, it was situated along a major international border and is often discussed in that context.
– 38th Parallel: Serves as the boundary (or armistice line/demarcation line) between North Korea and South Korea. It is a well-recognized international boundary.
– Dresden Line: Dresden is a major city in Germany. There is no recognized international boundary line known as the “Dresden Line”. It might refer to a historical or local feature, but not an international border.
Therefore, the “Dresden Line” is not an international boundary line.

– International boundary: A line separating countries.
– Durand Line: Afghanistan-Pakistan.
– Maginot Line: French defensive line along the German border.
– 38th Parallel: North-South Korea.
– Dresden is a city, not a boundary line.

Other famous boundary lines include the Radcliffe Line (India-Pakistan), McMahon Line (India-China), Oder-Neisse Line (Germany-Poland), and the Mason-Dixon Line (historical boundary in the US). Military defence lines along borders, like the Maginot Line or Siegfried Line, are distinct from officially demarcated political boundaries, but are often discussed in geographical and historical contexts related to international borders.

10. Which organisation prepares the topographical maps of India ?

Which organisation prepares the topographical maps of India ?

Geological Survey of India

Archaeological Survey of India

Survey of India

National Atlas and Thematic Mapping Organisation

This question was previously asked in

UPSC NDA-1 – 2016

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The Survey of India is the national mapping agency of India, under the Department of Science and Technology. It is responsible for producing topographic maps, which are detailed maps showing natural and man-made features, elevations, and contours of the land.

– Survey of India: National mapping and surveying agency.
– Topographical maps: Detailed representation of surface features.

– Geological Survey of India (GSI): Primarily involved in geological mapping and mineral exploration.
– Archaeological Survey of India (ASI): Deals with archaeological research and heritage preservation.
– National Atlas and Thematic Mapping Organisation (NATMO): Produces thematic maps and atlases focusing on specific themes like population, resources, etc., often based on data including topographic surveys.