UPSC CAPF

31. Which one of the following lenses would you prefer to use while readin

Which one of the following lenses would you prefer to use while reading very small letters printed on a label ?

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Convex lens of large focal length
Concave lens of large focal length
Convex lens of small focal length
Concave lens of small focal length
This question was previously asked in
UPSC CAPF – 2009
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A Convex lens of small focal length is preferred for reading very small letters printed on a label.
To read small letters, a magnifying glass is used. A magnifying glass is a convex lens. A convex lens forms a magnified, virtual, and erect image when the object is placed within its focal length. The magnification power of a simple magnifying glass is given by M = 1 + (D/f), where D is the least distance of distinct vision (approx. 25 cm) and f is the focal length of the lens. To achieve higher magnification, the focal length (f) must be smaller.
A concave lens is a diverging lens and produces reduced or same-size images (virtual and erect or real and inverted), not magnified images for viewing small objects directly. A convex lens of large focal length will produce less magnification compared to one with a small focal length.

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32. Sometimes, the consumption of local made alcoholic beverages may cause

Sometimes, the consumption of local made alcoholic beverages may cause blindness or even death. This may be because of contamination of the beverages with :

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Vinegar
Carbolic acid
Methyl alcohol
Formic acid
This question was previously asked in
UPSC CAPF – 2009
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Blindness or death from consuming local made alcoholic beverages may be because of contamination with Methyl alcohol.
Ethanol (ethyl alcohol) is the alcohol intended for consumption in alcoholic beverages. Methanol (methyl alcohol) is a highly toxic substance that can be produced as a byproduct during improper fermentation or distillation, or sometimes illegally added to beverages. When ingested, methanol is metabolized by the body into formaldehyde and formic acid, which are potent toxins that damage the optic nerve (leading to blindness) and other organs, often resulting in death.
Vinegar is primarily acetic acid, which is relatively harmless in small quantities. Carbolic acid is phenol, a highly corrosive and toxic chemical. Formic acid is one of the toxic metabolites of methanol, but the primary contamination is usually with methanol itself.

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33. In some parts of India, consumption of underground water causes mottle

In some parts of India, consumption of underground water causes mottled teeth and bone damage. Which one of the following is responsible for this malady ?

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Fluoride ion
Chloride ion
Oxide ion
Carbonate ion
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UPSC CAPF – 2009
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Fluoride ion is responsible for mottled teeth and bone damage caused by consuming contaminated underground water in some parts of India.
Excessive intake of fluoride, primarily through drinking water, leads to a condition called fluorosis. Dental fluorosis causes discoloration and mottling of tooth enamel, especially during tooth development. Skeletal fluorosis affects bones, causing joint pain, stiffness, and in severe cases, crippling deformities. Many areas in India have groundwater naturally high in fluoride.
While fluoride is essential for strengthening teeth enamel in appropriate amounts, its excess can be harmful. Chloride, Oxide, and Carbonate ions are common in water but are not the primary cause of mottled teeth and bone damage in the way that excess fluoride is.

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34. 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 :

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List-I (Process) List-II (Contaminant)
A. Aeration followed by filtration 1. Removal of colour
B. Reverse Osmosis 2. Removal of microorganism
C. Filtration through activated carbon 3. Removal of iron
D. Treatment with UV light 4. Removal of excess salts

Code:

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3 1 4 2
4 3 2 1
3 4 1 2
2 4 1 3
This question was previously asked in
UPSC CAPF – 2009
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The correct match between the water treatment processes and the contaminants removed is A-3, B-4, C-1, D-2.
– A. Aeration followed by filtration: Aeration oxidizes dissolved iron and manganese, forming precipitates that are then removed by filtration. Thus, it’s used for the removal of iron (3).
– B. Reverse Osmosis: This process uses a semipermeable membrane to remove dissolved salts and other impurities from water, effectively used for desalination or removal of excess salts (4).
– C. Filtration through activated carbon: Activated carbon is highly effective at adsorbing organic compounds, chlorine, and other substances that cause color, odor, and taste in water. Thus, it’s used for the removal of colour (1).
– D. Treatment with UV light: Ultraviolet (UV) light treatment is a disinfection method that inactivates microorganisms like bacteria and viruses by damaging their DNA. Thus, it’s used for the removal of microorganisms (2).
Matching the processes to the contaminants:
A. Aeration followed by filtration – 3. Removal of iron
B. Reverse Osmosis – 4. Removal of excess salts
C. Filtration through activated carbon – 1. Removal of colour
D. Treatment with UV light – 2. Removal of microorganism
This corresponds to the code 3 4 1 2, which is option C.

35. Villagers in some parts of India use the water extract of the ash obta

Villagers in some parts of India use the water extract of the ash obtained by burning banana plant as a substitute of soda. Which one of the following is the major active component in the extract ?

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Sodium Carbonate
Potassium Carbonate
Calcium Oxide
Magnesium Oxide
This question was previously asked in
UPSC CAPF – 2009
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The major active component in the water extract of ash obtained by burning banana plants, used as a substitute for soda, is Potassium Carbonate.
Plants absorb minerals from the soil, including potassium, sodium, calcium, and magnesium. When plant material is burned, the organic components are removed, leaving behind the mineral residues, primarily as carbonates or oxides. Banana plants are known to accumulate significant amounts of potassium. Burning plant material rich in potassium leads to the formation of potassium carbonate (K₂CO₃). This alkali compound, when extracted with water, yields a solution of potassium carbonate, which has alkaline properties similar to soda (sodium carbonate or sodium bicarbonate).
Historically, wood ash was a common source of potassium carbonate (potash), used in making soap, glass, and as a leavening agent (pearl ash). Different plant species yield ash with varying compositions, but potassium is often a dominant cation in land plants.

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36. Which one of the following chemicals is an artificial sweetener prescr

Which one of the following chemicals is an artificial sweetener prescribed to diabetic persons ?

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Aspartame
Glucose
Sucrose
Maltose
This question was previously asked in
UPSC CAPF – 2009
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Aspartame is an artificial sweetener prescribed to diabetic persons.
Diabetic persons need to manage their blood sugar levels. Glucose, Sucrose (table sugar), and Maltose are all types of sugars that significantly increase blood sugar. Artificial sweeteners like Aspartame provide sweetness with minimal or no calories and do not raise blood sugar levels, making them suitable alternatives for diabetics.
Aspartame is a low-calorie artificial sweetener made of two amino acids, aspartic acid and phenylalanine. It is much sweeter than sugar. Other common artificial sweeteners include Saccharin, Sucralose, Stevia, and Neotame.

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37. Which one of the following statements is not correct about Biosphere R

Which one of the following statements is not correct about Biosphere Reserves ?

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They are protected areas meant for conservation of Biodiversity
Each Biosphere reserve has three zones
There is a network of biosphere reserves world over
They were first started by IUCN (International Union for Conservation of Nature and Natural Resources)
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UPSC CAPF – 2009
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The statement that Biosphere Reserves were first started by IUCN (International Union for Conservation of Nature and Natural Resources) is not correct.
Biosphere Reserves were initiated by UNESCO (United Nations Educational, Scientific and Cultural Organization) under its Man and the Biosphere (MAB) Programme, which was launched in 1971.
A) They are protected areas meant for conservation of Biodiversity: This is correct. Biosphere reserves aim to conserve biodiversity and promote sustainable use of natural resources.
B) Each Biosphere reserve has three zones: This is correct. The typical zonation includes a core area (strictly protected), a buffer zone (allowing limited activities compatible with conservation), and a transition area (allowing sustainable economic and human activities).
C) There is a network of biosphere reserves world over: This is correct. Biosphere reserves form a global network under the MAB programme.
IUCN is a prominent international organization involved in nature conservation but did not originate the biosphere reserve concept.

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38. Which one of the following statements is not correct about “Flavr Savr

Which one of the following statements is not correct about “Flavr Savr” tomatoes ?

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It is genetically engineered
Its ripening process is slow
The fruit cannot be left on the plant for a long period
They have increased yield and better flavour
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UPSC CAPF – 2009
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The statement “The fruit cannot be left on the plant for a long period” is not correct about “Flavr Savr” tomatoes.
The Flavr Savr tomato was genetically engineered to slow down the ripening process by inhibiting the enzyme polygalacturonase. This characteristic allowed the tomato to stay on the vine longer, enabling it to develop more flavour before being harvested, and also extended its shelf life. Therefore, the fruit *could* be left on the plant for a longer period compared to conventional tomatoes picked green for transport.
A) It is genetically engineered: This is correct. Flavr Savr was the first commercially grown genetically engineered food.
B) Its ripening process is slow: This is correct. The genetic modification specifically targeted slowing down the ripening process.
D) They have increased yield and better flavour: The primary goal was better shelf life and allowing vine ripening for potentially better flavour. Increased yield was not a direct outcome of this specific modification. While allowing longer vine ripening might contribute to better flavour compared to artificially ripened tomatoes, claiming “increased yield and better flavour” as a definitive characteristic is debatable, but statement C is clearly and definitively incorrect based on the technology’s purpose.

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39. Which of the following is not true about Giant Panda ?

Which of the following is not true about Giant Panda ?

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It is a logo of WWF (Worldwide Fund for Nature)
Giant Pandas are naturally found in Tibet and Southwest China
Giant Pandas are worst invasive species of the world
Giant Pandas feed on Bamboos
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UPSC CAPF – 2009
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The Giant Panda (Ailuropoda melanoleuca) is a well-known symbol of conservation and is the logo of the World Wide Fund for Nature (WWF) (Statement A is true). They are native to a few mountain ranges in central China, primarily Sichuan, but also Shaanxi and Gansu provinces, which is part of Southwest China and historically related to Tibetan areas (Statement B is true). Their diet consists almost exclusively of bamboo (Statement D is true). Giant Pandas are critically endangered or vulnerable (status changes over time due to conservation efforts) native species, not invasive species. Invasive species are non-native species that cause harm to the new environment.
– Giant Pandas are native to China, primarily feeding on bamboo.
– They are the logo of WWF and are a vulnerable/endangered species.
– Giant Pandas are not invasive species; they are native to their habitat and are facing threats, not posing them to a new environment.
Conservation efforts, including habitat protection and breeding programs, have helped improve the status of Giant Pandas from endangered to vulnerable in recent years, although significant threats still remain.

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40. Aquatic animals breathe much faster than terrestrial animals because o

Aquatic animals breathe much faster than terrestrial animals because of :

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low amount of dissolved oxygen in water
low amount of hemoglobin in their blood
high metabolic rate of aquatic animals
large amount of dissolved nitrogen in water
This question was previously asked in
UPSC CAPF – 2009
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Aquatic animals breathe dissolved oxygen from water using gills or other specialized structures. The concentration of dissolved oxygen in water is significantly lower (only about 5-10 ml per litre, or 5-10 parts per million) and fluctuates more compared to the concentration of oxygen in air (about 210 ml per litre, or 210 parts per million). To extract sufficient oxygen from this lower concentration, aquatic animals need to process a much larger volume of water, resulting in faster breathing rates compared to terrestrial animals which breathe air with a much higher oxygen concentration.
– Dissolved oxygen levels in water are much lower than oxygen levels in the air.
– Aquatic animals breathe faster to compensate for the lower oxygen concentration in their environment.
Temperature and salinity affect the solubility of oxygen in water; higher temperatures and salinity generally lead to lower dissolved oxygen levels. This can further impact the breathing rates of aquatic animals.

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