EDITORIALS & ARTICLES

Hit List Questions 52-PPP 100 PRELIMS 2024 - 70

Questions & Explanations:

 

1.

In Electromagnetic spectrum from low to high frequency the correct order is

(a) gamma rays, x-rays, ultraviolet, visible light, infrared, radio waves and microwaves.

(b) gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves and radio.

(c) radio waves, microwaves, infrared, visible light, ultraviolet, gamma rays, and X-rays

(d) radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays

 

 

2.

Which of the following is/are true?

1. The energy of a wave is directly proportional to its frequency.

2. The frequency of wave is inversely proportional to its wavelength.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

 

3.

Which of the following is/are true?

1. The NavIC satellites use rubidium atomic clocks.

2. NavIC has a coverage area that includes India and a region up to 1500 km beyond Indian boundaries.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

 

4.

M23 rebels in news refer to the context of

(a) Yemen

(b) Congo

(c) Armenia

(d) Syria

 

5.

Consider the following statements:

1. Burning coal is a source of mercury.

2. There is no known safe exposure level for elemental mercury in humans, and effects can occur at even very low levels. 

3. The single largest source of human-made mercury emissions is the artisanal and small-scale gold mining sector. 

How many of the statements given above are correct?

(a) Only one 

(b) Only two 

(c) All three 

(d) None

6.

Consider the following:

1. electrons

2. muons

3. tau particles

4. neutrinos

Which of the above are Leptons?

(a) 1 and 2

(b) 2, 3 and 4

(c) 1, 3 and 4

(d) 1, 2, 3 and 4

 

7.

Which of the following is/are true?

1. Eugenol is extracted from the clove.

2. Attar oil is derived from rose.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

 

8.

I. An atom’s mass is slightly lower than the sum of the masses of protons, neutrons, and electrons.

II. The lightest known ‘magic’ nucleus is lead with 82 protons.

Which of the above statements is/are true?.

(a) Only I

(b) Only II

(c) Both I & II

(d) Neither I nor II

 

9.

Consider the following statements:

1.  Potassium Bromide is used as a sedative.

2.  Sodium benzoate is used as a food preservative.

3.  Sodium Oleate is a major component of detergents.

4.  Calgon is used as water softener.

5.  Di-ammonium Phosphate Contains 18% Phosphorus and 46% Nitrogen.

Of these.

(a) Only 1, 2 and 4 are correct

(b) Only 1 and 2 are correct

(c) Only 2, 3 and 5 are correct

(d) Only 2, 4 and 5 are correct

 

10.

1. 70% of the cosmos consist of dark energy, 25% dark matter and 5% normal matter.

2. Dark energy drives the accelerated expansion of the universe.

Which of the above statements is/are false?.

(a) Only 1
 

(b) Only 2
 

(c) Both 1 and 2
 

(d) Neither 1 nor 2

 

11.

Which one of the following pairs is correctly matched?

(1) Silver chloride

(a) Horn silver

(2) Zinc phosphide

(b) Rat poison

(3) Zinc oxide

(c) Philosopher’s wool

(4) Quick Silver

(d) Aluminium Borate

How many of these is/are correctly paired?.

(a) Only 1

(b) Only 2

(c) Only 3

(d) All the four

 

 

12.

Aspartame is an artificial sweetner sold in the market. It consists of amino acids and provides calories like other amino acids. Yet, it is used as a low-calorie sweetening agent in food items. What is the basis of this use?

(a) Aspartame is as sweet as table sugar, but unlike table sugar, it is not readily oxidized in the human body due to lack of requisite enzymes 

(b) When aspartame is used in food processing, the sweet taste remains, but it becomes resistant to oxidation 

(c) Aspartame is as sweet as sugar but after ingestion into the body, it is converted into metabolites that yield no calories 

(d) Aspartame is several times sweeter than table sugar, hence food items made with small quantities of aspartame yield fewer calories on oxidation

 

13.

Which of the following is/are true?

1. The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by the depletion of glucose.

2. Tri Nitro Glycerine is known as Nobel''s oil.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

 

14.

A person in a spaceship located half way between the earth and the sun will notice that the:

1. sky is jet black.

2. stars do not twinkle.

3. temperature outside the spaceship is much higher than that on the surface of the earth.

(a) 3 alone is correct

(b) 1 and 2 are correct

(c) 1 and 3 are correct

(d) 1, 2 and 3 are correct

 

15.

I. Electrons and positrons are leptons.

II. Positronium is a purely leptonic atom.

Which of the above statements is/are true?.

(a) Only I

(b) Only II

(c) Both I & II

(d) Neither I nor II

16.

Consider the following:

1. Mexico  

2. Pakistan 

3. Italy

4. India 

The founding members of Uniting for Consensus (UfC) include

(a) 1, 2 and 3

(b) 2 and 4 only

(c) 4 only

(d) 1, 3 and 4

 

17.

Total internal reflection can take place when light travels from

(a) diamond to glass

(b) water to glass

(c) air to water

(d) air to glass

 

18.

Th(is)ese (is)are the postulates of Quantum Physics.

1. Electrons are particles like the little marbles that we play with.

2. An electron does not emit energy when it is in a stationary state.

3. Electrons generally prefer to have lower energy.

(a) Only 2

(b) 2 & 3 

(c) Only 1 

(d) 1, 2 & 3

 

19.

1. The ionosphere is situated about 30-600 km above Earth''s surface.

2. The ionosphere expands and contracts in response to solar radiation.

(a) Only (1) is true

(b) Only (2) is true

(c) Both (1) & (2) are true

(d) Neither (1) Nor (2) is true

 

20.

Consider the following statements. 

1. Thorium is a fissile material.

2. To use the Thorium in India, Uranium-235 or Plutonium-239 is definitely needed.

Which of the statements given above is/are correct?  

(a) Only 1

(b) Only 2 

(c) Both 1 and 2 

(d) Neither 1 nor 2

 

21.

With reference to Newton’s law of universal gravitation, consider the following statements: 

1. The gravitational force between two objects is directly proportional to the product of their masses.

2. The gravitational force between two objects is inversely proportional to the square of the distance between them.

Which of these statements is/are incorrect?

(a) Only 1

(b) Only 2

(c) Both 1 and 2

(d) Neither 1 nor 2

 

22.

The foul smell of dead fish is due to

 (a) Amino compounds

 (b) Aldehydic compounds

 (c) Sulphur compounds

 (d) Nitro compounds

 

23.

Consider the following statements:

A 4-wheel vehicle moving in a sharp circular path at high speed will:

1. overturn about its outer wheels

2. overturn about its inner wheels

3. skid outwards

4. skid inwards

Which of these statements is/are correct?

(a) 1 and 3

(b) 2 and 4

(c)  2 and 3

(d) 1 and 4

 

24.

Printer''s ink is obtained by the decomposition of 

(a) acetylene 

(b) benzene 

(c) carbon tetrachloride

(d) methane

 

25.

Which of the following statements is/are correct?

1. The normal temperature of human on Kelvin scale is 310K.

2. At 160ºC the Fahrenheit temperature is double of Centigrade temperature.

3. The safest temperature for keeping food fresh in a refrigerator is 40ºF.

Select the correct answer using the codes given below.

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

 

EXPLANATIONS

 

1.

https://www.thehindu.com/sci-tech/science/glass-transparency-physics-explained/article67701897.ece

 

 

D    

2.

 

C   

3.

https://www.thehindu.com/sci-tech/technology/navic-and-its-integration-into-iphone-15-explained/article67311882.ece

https://www.thehindu.com/sci-tech/science/global-positioning-system-relativity-gnss-navic-explained/article67606417.ece 

C

4.

https://www.thehindu.com/news/international/eastern-congo-conflict-fighting-rwanda-explains-m23/article67912364.ece

B

5.

https://www.unep.org/news-and-stories/story/minamata-convention-mercury-marks-three-years-protecting-human-health-and#:~:text=The%20single%20largest%20source%20of,to%20the%20atmosphere%20every%20year.

https://www.unep.org/news-and-stories/story/how-minamata-convention-aiming-end-mercurys-millennia-long-toxic-run

C  

6.

A lepton is a particle not affected by the strong nuclear forces, but is only subjected to the weak forces. As such, electrons and neutrinos are leptons. A lepton number of 1 is assigned to both the electron and the neutrino and −1 to the antineutrino and the positron.

https://www.thehindu.com/sci-tech/science/this-particles-wobble-could-help-spot-cracks-in-the-laws-of-physics/article67442189.ece

D   

7.

Eugenol is a volatile phenolic constituent of clove essential oil obtained from Eugenia caryophyllata buds and leaves. It is a functional ingredient of numerous products which have been used in the pharmaceutical, food and cosmetic industry in restricted concentrations.

https://www.thehindu.com/videos/watch-how-is-the-famous-attar-of-kannauj-made/article67452778.ece#:~:text=India%20is%20the%20world''s%20largest,just%206%2D8ml%20of%20Attar.

C

8.

https://www.thehindu.com/sci-tech/science/in-pursuit-of-a-magic-number-physicists-discover-new-uranium-isotope/article66699249.ece

https://www.vedantu.com/physics/magic-number

A   

9.

·    The potassium bromide, or KBr, has been used as an anti-seizure drug in human and veterinary medicine for over a century.

·    Phenobarbital, or PB, has been used to treat seizures for years too.

·    Given the long history of widespread use of both medications, This drug is not FDA approved for treating seizures in humans or animals.

·    Potassium bromide is one of the standard anticonvulsant drugs used to treat canine and feline epilepsy and is often abbreviated as KBr.

·    This is often used in combination with Phenobarbital but can also be used by itself to regulate seizure activity.

Sodium benzoate is used as a preservative to prevent food from molding. It''s added to a wide variety of foods, including mayonnaise, margarine, carbonated drinks, jams and jellies, sauces, and tomato paste. It helps keep products shelf-stable for at least 2 years from the date of purchase and is used in concentrations of less than 0.5% by volume. It''s used in other household products, too, including mouthwash, lotion, and as a preservative in some medicines.

Permanent hardness is removed by Calgon process. In this process, Calgon is referred to Sodium hexametaphosphate and its chemical formula is given by Na6P6O18. This Calgon when added to hard water forms soluble complex.

Sodium oleate is the sodium salt of oleic acid, a monounsaturated fatty acid. This anionic surfactant and emulsifier is a component of commercial soaps.

Gun Powder

Gunpowder, also known as the retronym black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive.

It consists of a mixture of sulfur, carbon, and potassium nitrate. Sulfur and charcoal act as fuels while the saltpetre is an oxidizer.

 

Di-ammonium Phosphate is popularly known as DAP in India. It contains both Nitrogen and Phosphorus which are primary macro-nutrients and part of 18 essential plant nutrients. DAP Contains 18% Nitrogen and 46% Phosphorus (P2O5).

https://www.thehindu.com/business/Economy/russian-sellers-said-to-stop-fertiliser-discounts-to-india/article67300255.ece

https://indianexpress.com/article/explained/everyday-explainers/sitharaman-nano-dap-fertiliser-budget-9138989/#:~:text=Why%20Nano%20DAP,Rs%201%2C350%20for%20the%20bag).

Nano fertilisers are highly efficient types of fertilisers that provide nutrients like nitrogen to crops through fine granules.

DAP (Di-Ammonium Phosphate):

·    DAP is the second most commonly used fertilizer in India after urea.

·    DAP is a preferred fertilizer in India because it contains both Nitrogen and Phosphorus which are primary macro-nutrients and part of 18 essential plant nutrients.

·    Fertilizer grade DAP contains 18% Nitrogen and 46% Phosphorus. It is manufactured by reacting Ammonia with Phosphoric acid under controlled conditions in fertilizer plants.

Nano DAP:

·    Nano DAP is a specialised form of DAP designed with the goal of improving the fertiliser''s effectiveness in promoting plant growth and development.

·    In 2023 Indian Farmers Fertiliser Cooperative (IFFCO) launched its Nano DAP, containing 8% Nitrogen and 16% Phosphorus by volume.

·    Unlike conventional DAP, which comes in granular form, IFFCO’s Nano DAP is in liquid form.

A

10.

Dark Energy

  • It’s a theoretical form of energy that produces a negative and repulsive force, acting in the direction opposite to that of gravity. 
  • Impact: It causes the fabric of space itself to stretch and expand. It is thought to be responsible for the accelerating expansion of the universe.
  • There are four fundamental forces in our universe, and speculative theories have proposed a fifth force – something that can’t be explained by the four forces. The four forces are: 
    • Gravitational force.
    • Electromagnetic force.
    • Strong nuclear force.
    • Weak nuclear force.

Dark Matter

  • It is made up of particles that do not have a charge — which means they do not interact through electromagnetic interactions. 
  • Characteristics: These are particles that are “dark”, namely because they do not emit light, which is an electromagnetic phenomenon, and “matter” because they possess mass like normal matter and hence interact through gravity.

Dark Energy Vs Dark Matter

  • Over 95% of the universe comprises dark matter and dark energy, with visible matter making up less than 5%.

Aspects

Dark Energy

Dark Matter

Proportion in Universe

Constitutes about 68% of the universe.

Makes up approximately 27% of the universe.

Role

Acts as a repulsive force, driving the expansion of the universe.

Exerts gravitational attraction, holding galaxies together.

Visibility

Cannot be directly observed; remains elusive.

Cannot be directly observed; detected through gravitational effects.

Discovery

Discovered in 1998, following observations of accelerating cosmic expansion.

Proposed as early as the 1920s based on gravitational effects

 

C

11.

(1) Silver iodide

(b) Artificial rain

(2) Silver chloride

(a) Horn silver

(3) Zinc phosphide

(c) Rat poison

(4) Zinc oxide

(d) Philosopher’s wool

Zinc phosphide is an inorganic compound that is used in rat poison. 

Mercury is a chemical element; it has symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum. A heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.

Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide. Exposure to mercury and mercury-containing organic compounds is toxic to the nervous system, immune system and kidneys of humans and other animals; mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury) either directly or through mechanisms of biomagnification.

Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, although concerns about the element''s toxicity have led to the phasing out of such mercury-containing instruments.[8] It remains in use in scientific research applications and in amalgam for dental restoration in some locales. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent lamp produces short-wave ultraviolet light, which then causes the phosphor in the tube to fluoresce, making visible light.

C    

12.

·      Artificial sweetener is one of the most attractive substitutes to sugar as it does not add many calories to our diet.

·      It can be used directly in the processed food as in puddings, dairy products, candy, soft drinks, baked goods, jams and many other foods and beverages.

·      It can also be used after mixing it with starch-based sweeteners.

·      For a sweetening agent to work properly, a sweetener should be soluble in water and it should readily bind with a receptor molecule present on the surface of the tongue.

·      Common Artificial Sweetener: Saccharin, Aspartame.

Aspartame:

·      In 1879 Aspartame was discovered and it was found that it is approximately 200 times sweeter than sugar.

·      It is not readily oxidized in the human body due to a lack of requisite enzymes.

·      It is a dipeptide methyl ester and its name is aspartyl phenylalanine-1-methyl ester.

·      It is commonly used as a tabletop sweetener and is also used in a variety of foods.

·      When it is heated it breaks down into amino acids and loses its sweetness, so it cannot be used for baked foods.

·      As it becomes unstable at cooking temperature, it is only used in soft drinks and cold foods.​

13.

The sensation of fatigue in the muscle after prolonged strenuous physical work is caused due to accumulation of lactic acid, which is formed because of anaerobic respiration in the absence of oxygen.

Tri Nitro Glycerin (TNG) also known as Nobel Oil, is an explosive fluid. TNG is prepared by the addition of sulfuric acid and nitric acid to glycerine. It is a colorless oily liquid. TNG is used in the preparation of dynamite. Therefore it is also known as Nobel''s oil.

C  

14.

There is a presence of atmosphere at earth''s surface which consists of thick and moving layers of air. The dust particles, particulates, smog, water vapour and smoke are also present in air. Stars twinkle when we see them from the Earth''s surface because we are viewing them through thick layers of turbulent (moving) air in the Earth''s atmosphere. As their light travels through the many layers of the Earth''s atmosphere, the light of the star is bent (refracted) many times in random directions (light is bent when it hits a change in density –like a pocket of cold air or hot air). This random refraction results in the star as its twinkling but for a person in spaceship no such refractions are possible as there is vaccum in space. Thus, star will not twinkle.

Similarly, sky will appear blue to us due to Rayleigh scattering which is again due to presence of atmosphere on earth''s surface. The shorter wavelength light is absorbed by the gas molecules of atmosphere. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Some of this scattered blue light reaches you. Since, you see, the sky looks blue. Whereas no atmosphere is there in space thus, no absorbing and scattering is possible that''s why for a person in spaceship sky appears black.

Temperature outside the spaceship is higher in comparison to earth''s surface because of being nearer to sun.

D   

15.

https://www.thehindu.com/sci-tech/science/raman-research-institute-international-collaboration-of-physicists-demonstrates-laser-cooled-positronium/article67875811.ece

16.

Uniting for Consensus (UfC) 

·    It is also known as the Coffee Club.

·    It is a movement that developed in the 1990s in opposition to the possible expansion of permanent seats in the United Nations Security Council.  

·    It is established in 1995 by Italy, Pakistan, Mexico and Egypt. 

·    Aim- to counter the bids for permanent seats proposed by G4 nations (Brazil, Germany, India, and Japan)  

·    The founders of the group were soon joined by other countries, including Spain, Argentina, Turkey, and Canada, and in a short time the group came to include about 50 countries in Asia, Africa, and Latin America. 

·    The thesis of the Uniting for Consensus group is that any increase in permanent seats would further accentuate the disparity between the member countries.

https://www.thehindu.com/news/international/want-to-see-expansion-of-unsc-permanent-seats-to-include-india-brazil-germany-japan-uk/article67040143.ece

17.

Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary, no light can pass through and all light is reflected. The critical angle is the angle of incidence above which the total internal reflection occurs. Total internal reflection takes place when light travels from optically denser medium to optically rarer medium. Refractive index of diamond is very high (2.417) whereas refractive index of glass is only in between (1.5 to 1.6), whereas in rest all options there is no possibility of total internal reflection because refractive index of  water (1.33) and air (1.0008) is less than refractive index of glass.

A      

18.

https://www.thehindu.com/sci-tech/science/fermi-energy-copper-quantum-physics-explained/article66845396.ece

B

19.

The ionosphere is situated about 30-600 miles (50-950 km) above Earth''s surface.

https://www.thehindu.com/sci-tech/science/gamma-ray-burst-in-faraway-galaxy-disturbed-earths-upper-atmosphere/article67544907.ece

20.

Thorium is a fertile material and not a fissile material.

https://www.thehindubusinessline.com/business-tech/this-new-nuclear-fuel-can-guarantee-indias-green-energy-transition/article67716078.ece

21.

https://www.thehindu.com/sci-tech/science/the-gravitational-constant-what-is-it/article67473040.ece

D

22.

Specific odor of dead fish is due to trimethyl amine when fish are killed, bacteria and fish enzymes convert Trimethylamine N-oxide (TMAO) into trimethylamine (TMA), which gives off the characteristic “fishy” odor.

https://www.thehindu.com/sci-tech/science/smell-a-fish/article32937234.ece

23.

If a four-wheeler is moving faster than the relative speed then it skids outwards but then the frictional force provides the necessary centripetal force which ensures the car to have a curved path. On sharp circular path if the outer portion ofthe road is not raised, then the vehicle will skid outward andwill overturn about its outer wheels.

A  

24.

Carbon black is produced during the furnace process mostly by burning natural gas, which has methane as a predominant compound. This carbon black can be used in various industries such as printing inks.

https://www.vedantu.com/chemistry/carbon-black

25.

°F = °C×(9/5)+32.

K = °C + 273.15.

https://foscos.fssai.gov.in/consumergrievance/tips-for-safe-food

 







POSTED ON 03-06-2024 BY ADMIN
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