2021

101. The two elements which are present in proteins but generally absent in

The two elements which are present in proteins but generally absent in carbohydrates are

[amp_mcq option1=”Carbon and Hydrogen.” option2=”Carbon and Nitrogen.” option3=”Nitrogen and Sulphur.” option4=”Sulphur and Hydrogen.” correct=”option3″]

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Proteins are complex organic molecules that always contain carbon, hydrogen, oxygen, and nitrogen. Many proteins also contain sulphur (due to the presence of amino acids like cysteine and methionine). Carbohydrates are primarily composed of carbon, hydrogen, and oxygen, usually in a ratio of CnH2nOn or similar forms. Therefore, nitrogen and sulphur are elements typically found in proteins but generally absent in carbohydrates.
Proteins are polymers of amino acids. Each amino acid contains an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a side chain (R-group) attached to a central alpha carbon. The nitrogen atom is a defining component of the amino group. Carbohydrates, such as sugars and starches, are primarily composed of carbon, hydrogen, and oxygen atoms, often in a 1:2:1 ratio for H:O.
While nitrogen is a constituent of proteins and nucleic acids (DNA, RNA), it is not found in carbohydrates or typical lipids. Sulphur is present in some amino acids (cysteine, methionine) and therefore in many proteins, as well as in some vitamins, but it is not a component of carbohydrates. Carbon and hydrogen are fundamental elements present in all organic molecules, including both proteins and carbohydrates.

102. Isotope of Cobalt is used in the treatment of

Isotope of Cobalt is used in the treatment of

[amp_mcq option1=”Cancer.” option2=”Goitre.” option3=”Beriberi.” option4=”Crohn’s disease.” correct=”option1″]

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The radioactive isotope Cobalt-60 (⁶⁰Co) is widely used in medicine, particularly in radiotherapy for the treatment of cancer. It emits gamma rays which are used to kill cancer cells.
Isotopes are atoms of the same element with different numbers of neutrons.
Radioactive isotopes (radioisotopes) decay, emitting radiation.
⁶⁰Co is a common source of gamma rays for external beam radiotherapy machines (historically known as ‘cobalt bombs’).
While radiotherapy is a key use, ⁶⁰Co is also used for sterilization of medical equipment and food irradiation due to its potent gamma radiation. Goitre is often treated with Iodine-131.

103. When electricity is passed through brine, it produces

When electricity is passed through brine, it produces

[amp_mcq option1=”NaCl” option2=”NaOH” option3=”KCl” option4=”KOH” correct=”option2″]

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The electrolysis of brine (a concentrated aqueous solution of sodium chloride, NaCl) is an industrial process that produces sodium hydroxide (NaOH), chlorine gas (Cl₂), and hydrogen gas (H₂). The overall reaction is 2NaCl (aq) + 2H₂O (l) → 2NaOH (aq) + Cl₂ (g) + H₂ (g).
Brine is a solution of NaCl in water.
Electrolysis is the process of using electricity to drive a non-spontaneous chemical reaction.
The products are sodium hydroxide, chlorine, and hydrogen.
This process is known as the chlor-alkali process and is a major industrial method for producing these three important chemicals. NaOH is a strong base used in many industries, while Cl₂ is used for disinfection and manufacturing, and H₂ is used as a fuel or in chemical synthesis.

104. Chips bags contain which gas ?

Chips bags contain which gas ?

[amp_mcq option1=”Oxygen” option2=”Hydrogen” option3=”Carbon dioxide” option4=”Nitrogen” correct=”option4″]

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Chips bags are filled with nitrogen gas. Nitrogen is an inert gas that helps prevent oxidation of the chips, which causes them to become stale and rancid. It also provides cushioning, protecting the fragile chips from breaking during transport and handling.
Nitrogen gas is inert, meaning it does not react readily with the food.
Oxygen would react with the fats in the chips, causing rancidity.
The gas also helps maintain the structural integrity of the chips.
This process of flushing food packaging with an inert gas is called Modified Atmosphere Packaging (MAP) and is commonly used for various food products to extend shelf life.

105. Conversion of limestone to quick lime is an example of

Conversion of limestone to quick lime is an example of

[amp_mcq option1=”decomposition reaction.” option2=”substitution reaction.” option3=”combination reaction.” option4=”double decomposition reaction.” correct=”option1″]

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Limestone is primarily calcium carbonate (CaCO₃). Quick lime is calcium oxide (CaO). The conversion of limestone to quick lime involves heating calcium carbonate to a high temperature, which causes it to break down into calcium oxide and carbon dioxide gas: CaCO₃ (s) → CaO (s) + CO₂ (g). This reaction where a single compound breaks down into two or more simpler substances is called a decomposition reaction.
Decomposition reaction: A single reactant breaks down into simpler products.
Combination reaction: Two or more reactants combine to form a single product.
Substitution reaction: An atom or group is replaced by another atom or group.
Double decomposition reaction: Two compounds exchange ions or groups to form two new compounds.
This process, the thermal decomposition of calcium carbonate, is known as calcination or lime burning and is carried out in a kiln.

106. pH of blood is

pH of blood is

[amp_mcq option1=”7·0″ option2=”6·5″ option3=”7·15″ option4=”7·40″ correct=”option4″]

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The pH of healthy human blood is maintained within a narrow range of 7.35 to 7.45. This slightly alkaline range is crucial for proper metabolic function. Option D, 7.40, falls within this normal range and is often cited as an average value.
pH measures the acidity or alkalinity of a solution.
A pH of 7 is neutral. Below 7 is acidic, and above 7 is alkaline (basic).
Maintaining blood pH homeostasis is vital for physiological processes.
Deviations from the normal blood pH range can lead to serious health conditions such as acidosis (pH below 7.35) or alkalosis (pH above 7.45). The body has buffer systems to help maintain this narrow pH range.

107. Who among the following is known as the Father of Nuclear Physics ?

Who among the following is known as the Father of Nuclear Physics ?

[amp_mcq option1=”E. Rutherford” option2=”J.J. Thomson” option3=”Niels Bohr” option4=”James Chadwick” correct=”option1″]

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Ernest Rutherford (E. Rutherford) is widely regarded as the “Father of Nuclear Physics”. His experiments, particularly the gold foil experiment, led to the discovery of the atomic nucleus and the idea that the atom is mostly empty space. He also coined the terms “alpha” and “beta” rays, discovered the proton, and performed the first artificial nuclear transmutation.
Rutherford’s work revolutionized the understanding of atomic structure and radioactivity.
J.J. Thomson discovered the electron.
Niels Bohr developed an early model of the atom based on quantum mechanics.
James Chadwick discovered the neutron.
Rutherford received the Nobel Prize in Chemistry in 1908 for his investigations into the disintegration of the elements, and the chemistry of radioactive substances.

108. Sodium chlorate is used in

Sodium chlorate is used in

[amp_mcq option1=”textile printing and dyeing.” option2=”match industry.” option3=”antiseptics.” option4=”disinfectants.” correct=”option1″]

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Sodium chlorate (NaClO₃) is a strong oxidizing agent. It is widely used in the textile industry as an oxidizing agent for dyeing and printing processes. It is also used in the production of chlorine dioxide, a bleaching agent.
Sodium chlorate is a chemical compound with the formula NaClO₃.
Its primary uses leverage its strong oxidizing properties.
Sodium chlorate is also used as a weedkiller, defoliant, and in some fireworks and explosives formulations, although potassium chlorate is more common in pyrotechnics.

109. Which one among the following is a non-luminous object ?

Which one among the following is a non-luminous object ?

[amp_mcq option1=”Sun” option2=”Candle” option3=”LED bulb” option4=”Moon” correct=”option4″]

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A non-luminous object is an object that does not produce its own light. It is visible because it reflects light from a luminous source. The Moon does not produce its own light; it reflects sunlight.
Luminous objects emit light (e.g., Sun, candle flame, light bulb).
Non-luminous objects reflect light (e.g., Moon, planets, furniture, books).
The apparent brightness of non-luminous objects depends on the intensity of the incident light and their reflective properties.

110. Light waves are

Light waves are

[amp_mcq option1=”progressive in nature.” option2=”mechanical in nature.” option3=”longitudinal in nature.” option4=”transverse in nature.” correct=”option4″]

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Light waves are electromagnetic waves, which means they are fluctuations of electric and magnetic fields. Electromagnetic waves, including light, are characterized by their transverse nature, where the oscillations of the fields are perpendicular to the direction of wave propagation.
Transverse waves have oscillations perpendicular to the direction of energy transfer (propagation).
Longitudinal waves have oscillations parallel to the direction of energy transfer (propagation), like sound waves in air.
Light is non-mechanical; it does not require a medium to travel.
The electromagnetic spectrum includes various types of waves like radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays, all of which are transverse electromagnetic waves.
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