English Comprehension PYQs

The correct answer is 1 and 4 only.

Key Points

• Myopia or nearsightedness:
• In this condition, the person can see nearby objects but is not able to see distant objects.
• Excessive curvature of the eye lens leads to myopia.
• The elongation of the eyeball results in a defect of vision called nearsightedness or myopia.
• Myopia occurs when light rays bend in the wrong direction due to the shape of the eyes, causing the image to be focused in front of the retina instead of on the retina.
• Nearsightedness can be corrected by using concave lenses.

Additional Information

• Hypermetropia or Far-sightedness:
• Hypermetropia is commonly known as far-sightedness and convex lenses are used to treat it.
• In this condition, the person can see distant objects but is not able to see nearby objects.
• Hypermetropia arises either because
• (i) the focal length of the eye lens is too long, or
• (ii) the eyeball has become too small.
• Hypermetropia occurs when light rays from a nearby object focus on a point behind the retina.

The correct answer is Vb > Va > Vc.

Key Points

• To find the speed from a distance-time graph, you need to calculate the slope of the graph at any given point.
• The slope represents the rate of change of distance concerning time, which is the definition of speed.
• The formula for speed (v) is given by the ratio of the change in distance to the change in time:
• \(v = {\Delta d \over \Delta t}\)
• Here, 
• v is the speed,
• Δd is the change in distance, and
• Δt is the change in time.
• In the given graph, the order of decreasing slope is given by b>a>c.
• Hence, the velocity in decreasing order is given by Vb > Va > Vc

The correct answer is At infinity.

Key Points

To find the position of the image formed by a concave mirror, you can use the mirror formula:

• \({1\over f} = {1\over u}+{1\over v}\)
• where:
• f is the focal length of the mirror,
• u is the object distance (distance of the object from the mirror),
• v is the image distance (distance of the image from the mirror).
• The focal length ( f) for a concave mirror is considered negative.
• Given:
• Radius of curvature (R) = -50 cm (negative for concave mirror)
• Object distance (u) = -25 cm (negative since the object is on the same side as the incident light for a concave mirror)
• First, find the focal length using the relationship : f = R/2
• �=(−50 cm)2=−25 c�=(−50 cm)2=−25 c�=(−50 cm)2=−25 c \({f} = {-50:cm\over 2} = -25:cm\)

Now, substitute the values into the mirror formula:

1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�1(−25)=1(−25)+1�[Math Processing Error] \({1\over -25} = {1\over -25}+{1\over v}\)

Solve for v:

\({1\over v} = {1\over -25}-{1\over -25} \)

\({1\over v} = {0}\)

\(\Rightarrow v = \infty\)

This implies that v is at infinity. In the case of a concave mirror, when the image distance (v) is positive infinity, the image is formed at the focus of the mirror.

The correct answer is increase to four times of its original value.

Key Points

• If the Moon has twice the mass that it does, the force between the Earth and the Moon would be twice as large.
• \(F = {G \times (Mass :of :moon) \times (Mass :of :Earth) \over distance^2} \)
• So, if the Moon was twice as massive, the attractive force of Earth on the moon be twice as large and the attractive force of the moon on Earth would be both twice bigger.
• If the Moon were half the distance from the Earth, the gravitational force would be four times as large
• \(F = {G \times (Mass :of :moon) \times (Mass :of :Earth) \over distance^2}\)
• According to the formula, it is visible that if the moon were half the distance from the Earth, the gravitational force would be four times as large.

The correct answer is greater than the speed of sound.

Key Points

• When a source of sound travels faster than the speed of sound, a shock wave is generated which gives rise to a sonic boom.
• These shock waves carry with them a huge amount of energy and pressure difference and those waves create a very loud and strong sound which is called sonic boom.
• It generates huge amounts of sound energy. It almost feels like the sound of thunder.
• The shock wave creates a cone of pressurized air molecules. As the cone spreads across the landscape along the flight path, it produces a continuous sonic boom along the entire width of the cone's base.
• The rapid release of pressure following the build-up by the shock wave is heard as a sonic boom.
• It is the sudden change in pressure (rate of change) that makes the sonic boom audible.

The correct answer is Au, Sn, Pb.

Key Points

• Gold (Au):
• Gold is a transition metal with the chemical symbol Au, which is derived from the Latin word "aurum".
• Its atomic number in the periodic table is 79 and it is known for its distinctive yellow color, ductility and high conductivity.
• Tin (Sn):
• Tin is a transition metal with the chemical symbol Sn, which is derived from the Latin word "stannum".
• Its atomic number is 50 and it is commonly used in the production of alloys such as bronze and solder.
• Lead (Pb):
• Lead is also a transition metal with the chemical symbol Pb, which is derived from the Latin word "plumbum".
• Its atomic number is 82 and it is known for its dense and flexible properties.

Additional Information

• Gallium
• It has the symbol Ga.
• Atomic number 31.
• Astatine
• It has the symbol At
• Atomic number 85.
• Antimony
• It has the symbol Sb
• Atomic number 51.

The correct answer is 95 - 97%.

Key Points

• On Venus and Mars, carbon dioxide is the dominant component making up 95–97% of the gaseous components on these planets.
• Carbon dioxide is an important gaseous component of the environment.
• It is stabilized by green plants through the process of photosynthesis. It is released during expiration by the process of respiration.

Additional Information

• Venus has a large troposphere in its atmosphere.
• Within the troposphere, gas is heated from below and slowly rotates, rising near the equator and descending at the poles.
• Venus is Earth's twin planet because it has an atmosphere.
• The atmosphere of Venus contains carbon dioxide with clouds of sulfuric acid droplets.
• Nitrogen is the second most common gas in the atmosphere of Venus.
• Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, larger only than Mercury.

The correct answer is Electrochemical method.

Key Points

• The electrochemical method is used to separate elements in a compound through processes like electrolysis, where electrical energy is used to drive a non-spontaneous reaction.
• During electrolysis, compounds such as water (H₂O) or sodium chloride (NaCl) are broken down into their constituent elements, like hydrogen and oxygen, or sodium and chlorine.
• This method is widely applied in industries such as metal extraction (e.g., aluminum from bauxite using Hall-Héroult process).
• Electrochemical separation is a clean and efficient way to isolate elements from ionic compounds, especially when thermal decomposition is not feasible.
• It relies on the movement of ions in an electrolytic solution and requires an external power source to initiate the reaction.

Additional Information

• Electrolysis
• A technique where electric current is passed through a substance to effect a chemical change.
• Used in the purification of metals and the production of chemical compounds like chlorine gas and sodium hydroxide.
• Ionic Compounds
• Compounds composed of ions held together by electrostatic forces called ionic bonding.
• These are the typical targets for electrochemical decomposition due to their charged nature.
• Electrodes
• Two conductors used in electrolysis: anode (positive) and cathode (negative).
• Different reactions occur at each electrode, leading to the separation of elements.
• Applications in Industry
• Used in extraction of reactive metals like aluminum, electroplating, and water treatment plants.
• Also employed in hydrogen production as part of renewable energy systems.

The correct answer is Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O (l).

 Key Points

• While whitewashing, Ca(OH)2 reacts slowly with CO2 in the air to form a thin layer of CaCO3 on the walls.
• Ca(OH)2 is Calcium hydroxide, CO2 is Carbon dioxide, and CaCO3 is Calcium carbonate.
• Calcium carbonate is formed 2-3 days after whitewashing, and thus we get a shiny finish on the wall.
• The following reaction takes place in the given case:
• Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O (l)

 Additional Information

• The common name of Calcium hydroxide is 'slaked lime' and the saturated solution of Calcium hydroxide is known as 'limewater'.
• Calcium carbonate is commonly known as 'limestone'.
• CaO is Calcium oxide.
• CaSO4 is Calcium sulphate.
• CaCl2 is Calcium chloride.

The correct answer is 3Fe + 4H2O → Fe3O4 + 4H2.

Key Points

• Balancing chemical equations involves adding stoichiometric coefficients to the reactants and products.
• This is important because a chemical equation must obey the law of conservation of mass and the law of constant proportions, i.e. equal numbers of atoms of each element must be present on the reactant side and product side of the equation.
• The chemical reaction is given as
• Fe + H_{2 O → Fe_{3 O_{4 + H₂}}}
• The balanced chemical equation can be written as
• Reactant         Products
• Fe = 1                Fe = 3
• H = 2                  H = 2
• O = 1                  O = 4
• 3Fe + 4H_{2 O → Fe_{3 O_{4  + 4H₂}}}

The correct answer is arrangement of leaves. 

Key Points

• Phyllotaxy refers to the pattern or arrangement of leaves on a plant's stem or branch.
• The arrangement of leaves on the stem of a plant is phyllotaxy. A structure similar to a leaf is a leaflet.
• Compound leaves come together to form several leaflets.
• Stipules are leaf-like structures found at the base of the stalk.
• The simple arrangement of leaves on a stem is opposite and alternating (also called a spiral).
• If multiple leaves are visible or appear to be, the leaves may also be rooted from the same point on the stem (at the same node).

Additional Information

• Phyllotaxy is of three types-
• Opposite - In opposite leaf arrangement, each node has a pair of leaves opposite each other.
• Alternate - In an alternate leaf arrangement, there is one leaf per plant node.
• Whorled - In whorled leaf arrangement, a node has more than two leaves in the form of a whorl.

The correct answer is proteins.

Key Points

• In the nucleus of each cell, DNA molecules are packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled around proteins called histones that support its structure.
• Chromosomes are highly condensed forms of chromatin threads.
• Chromosomes were first observed in pollen mother cells of Tradescantia by Hofmeister and Carl Naegeli.
• The credit for the discovery of chromosomes goes to Strasburger as he was the first to describe the chromosome structure seen in the nucleus during cell division.
• Typically, chromosomes are rod-shaped, elongated, or point-shaped ranging in size from 0.5 to 32 micrometers.

Additional Information

• In humans, each cell normally has 23 pairs of chromosomes, a total of 46.
• Twenty-two of these pairs, called autosomes, look the same in both men and women.
• The 23^rd pair, the sex chromosomes, differ between males and females.
• Females have two copies of the X chromosome, while males have one X and one Y chromosome.

The correct answer is Nucleoid.

Key Points

• In prokaryotic organisms, the nuclear region is not surrounded by any membrane.
• The undefined nuclear region lacking a nuclear membrane and containing only DNA without proteins in bacteria is called the nucleoid.
• Prokaryotic cells are primitive organisms.
• In prokaryotes, the nucleoid contains all or most of the genetic material.
• In prokaryotic cells, the nucleus is not well-defined because it is not surrounded by the nuclear membrane.

Additional Information

• A nucleosome is a section of DNA wrapped around a core of protein.
• Inside the nucleus, DNA forms a complex with a protein called chromatin, which allows the DNA to condense into small amounts.
• A nucleus, as it relates to genomics, is a membrane-bound organelle within a cell that contains chromosomes.
• A series of pores, or pores, in the nuclear membrane allow selective passage of certain molecules (such as proteins and nucleic acids) in and out of the nucleus.
• Nucleoproteins are a type of proteins that are associated with nucleic acids and ribosomes and lipoproteins, they often serve as lipid transport and storage proteins such as vitelline.
• A nucleoprotein is a conjugated protein structure consisting of a protein linked to a nucleic acid, either DNA abbreviated as deoxyribonucleic acid or RNA abbreviated as ribonucleic acid.

The correct answer is 1 - cell wall; 2 - cell membrane; 3 - endoplasmic reticulum; 4 - nucleus; 5 - vacuole.

Key Points

• Cell membrane
• Cell membrane is also called the plasma membrane.
• It can be observed only through an electron microscope.
• The plasma membrane is the outermost covering of the cell that separates the contents of the cell from its external environment.
• Cell wall
• Plant cells, in addition to the plasma membrane, have another rigid outer covering called the cell wall. The cell wall lies outside the plasma membrane.
• The plant cell wall is mainly composed of cellulose. Cellulose is a complex substance and provides structural strength to plants.
• Vacuoles
• Empty structure in the cytoplasm is called vacuole.
• Large vacuoles are common in plant cells. Vacuoles in animal cells are much smaller.
• Vacuoles are storage sacs for solid or liquid contents.
• Endoplasmic reticulum
• The endoplasmic reticulum (ER) is a large network of membrane-bound tubes and sheets. It looks like long tubules or round or long bags (vesicles).
• There are two types of ER ––
• rough endoplasmic reticulum (RER) and
• smooth endoplasmic reticulum (SER).
• Nucleus
• It is an important component of the living cell.
• Nucleus is separated from the cytoplasm by a double layered membrane called the nuclear membrane.

The correct answer is Telugu.

Key Points

• Krishnadevaraya was one of the important emperors of the Vijayanagara Empire who ruled from 1509–1529.
• He himself wrote his great work Amuktamalyada in Telugu.
• He was the third ruler of the Tuluva Dynasty.
• He is also known as Andhra Bhoja and Kannada Rajya Ramana.
• He built the Vithalaswamy Temple and Hazar Rama Temple in the Hoysala style of architecture.
• Krishnadev Rai always respected all sects of Hindu religion.
• During his reign, the Portuguese travelers, Domingo Paes and Durate Barbosa, visited his court.

The correct answer is It refers to monks, who migrated to the south of Vindhyas in 4^th century BCE.

Key Points

• The Digambara and Shvetambara sects primarily differ in their views on ascetic practices, particularly the wearing of clothes.
• The Shvetambaras regard canonical literature as true and sacred, such as the 12 Angas and Sutras.
• The Shvetambara Sect of Jainism does not have a historical connection with migration to the south of the Vindhyas.
• The migration to the south of the Vindhyas is not a distinguishing factor between these sects.

Additional Information

• Jains are divided into two major sects:
• ​The Digambara (meaning sky-clad or naked) sect.
• The Svetambara (meaning white-clad) sect.
• Both sects follow five vows of Jainism-
• ​Non-violence (Ahimsa)
• Truth (Satya)
• Non-stealing (Asteya)
• Celibacy/chastity (Brahmacharya)
• Nonattachment/ non-possession (Aparigraha

The correct answer is Odisha.

Key Points

• Vikramkhol Cave is located near Jharsuguda, Odisha and is situated in the reserved forest of Belpahar Range at a distance of 12 km from Belpahar.
• The inscriptions at Vikramkhol Cave are written using red ocher paint on an uneven rock surface in a natural rock shelter, which is then carved into the rock.
• The inscriptions were discovered around 1930 and first studied by Dr. K.P. Jaiswal.

Additional Information

• Monuments of Odisha:
• Sun Temple, Konark
• Sri Jagannath Puri Temple, Puri
• Dhauli, Bhubaneswar, Odisha
• Barabati Fort, Cuttack
• Khandagiri Caves, Bhubaneswar
• Brahmeshwara Temple, Bhubaneswar
• Lingaraj Temple, Bhubaneswar
• Sambalpur, Odisha Sambalpur

The correct answer is 2 only.

Key Points

• Levalloisian stone-flaking technique, the tool-making technique of prehistoric Europe and Africa, is characterized by the production of large flakes from the tortoise core (the finished core is shaped like an inverted tortoiseshell).
• This technique was more sophisticated than earlier methods of lithic reduction, which involved removing lithic flakes from prepared lithic cores.
• A striking platform is created at one end and the edges of the core are then cut by slicing around the outline of the desired lithic layer.
• The Levallois technique is not related to the making of perforated Harappan pottery.
• Harappa refers to one of the major sites of the Indus Valley Civilization, and Levallois technology is not associated with it.

Additional Information

• Harappa was first excavated by Dayaram Sahni in 1921.
• The Indus Valley Civilization was larger than the ancient Egyptian and Mesopotamian civilizations.
• Major findings
• Piece of Pottery with Indus Script
• Cubical Limestone Weight
• Faience Slag
• Sandstone statues of Human anatomy
• Copper Bullock cart
• Granaries
• Coffin burials (Only founded in Harrapa)
• Terracotta Figurines

The correct answer is 1 and 2 only.

Key Points

• The Bakshali Manuscript:
• It is indeed written in the Gatha language (a refined version of old Prakrit) using the Sharada script.
• It deals with topics such as fractions, square roots, arithmetic, and geometric progressions. Hence, statement 1 is correct.
• Aryabhatta and π (pi):
• In the field of geometry, Aryabhatta described the various properties of a circle giving a very accurate value for pi (π) correct to four decimal places at 3.1416
• In other words, what Aryabhata said was that the circumference of a circle with a diameter of 20000 is (4+100) x8 +62000= 62832.
• And we know that the value of pi is the ratio of the circumference to the diameter so in this case 62832/20000, which is incredibly 3.1416. Hence, statement 2 is correct.
• Sharangadhara Samhita:
• This text is not primarily focused on the political system of ancient India.
• The Sharangadhara Samhita is more known for its contributions to Ayurveda and pharmacology.
• It was written by Acharya Sharangadhara, the son of Sri Damodara and grandson of Raghavadev. Hence, statement 3 is incorrect.

Important Points

• The "Arthashastra" is a classical treatise on statecraft, politics, economics, and military strategy attributed to Chanakya (Kautilya), an ancient Indian scholar, teacher, economist, and political strategist who is traditionally identified with Chanakya, the adviser to Chandragupta Maurya, the founder of the Mauryan Empire.

The correct answer is Act of 1947 laid down the basic framework of the Indian Constitution.

Key Points

• The Indian Independence Act of 1947 did not lay down the basic framework of the Indian Constitution.
• The task of drafting the Indian Constitution was later undertaken by the Constituent Assembly of India, which was elected to represent the people of India.
• The drafting of the Indian Constitution took several years and was completed on 26 January 1950, when it came into force.

Additional Information

• Indian Independence Act, 1947:
• The Indian Independence Act, of 1947 received royal assent and entered into force on 18^th July 1947.
• It was primarily concerned with the transfer of legislative authority to the two new Dominions, India and Pakistan, and the delimitation of their territories.
• It gave the constituent assemblies of the two dominions unlimited power to make and adopt any constitution and to repeal any Act of the British Parliament which was prejudicial to their interests, including the Act of Independence.