English Comprehension PYQs

Explanation: 

• During exercise, our muscles require energy to contract and relax. This energy is primarily derived from glucose, which is broken down through a process called glycolysis. Glycolysis produces a molecule called pyruvate, which is then used to generate ATP, the energy currency of the cell.
• However, during intense exercise, the demand for energy can outstrip the supply of oxygen to the muscles. In this situation, the body switches to a different metabolic pathway called anaerobic respiration, which produces ATP without using oxygen.
• One of the byproducts of anaerobic respiration is lactic acid. Lactic acid is produced when pyruvate is converted into lactate by the enzyme lactate dehydrogenase. Lactic acid can build up in the muscles during intense exercise, leading to a decrease in pH and a sensation of burning or cramping in the muscles.

Therefore, when a sprinter feels cramps and pain in the thigh muscles after a run. This is due to accumulation of lactic acid.

Thus, the correct answer is option (1)

Key Points

• The leaf plucked from the plant on a sunny day has chlorophyll pigments that give the leaf its green colour.
• Chlorophyll is the primary pigment involved in photosynthesis, which converts light energy into chemical energy in plants.
• The given experiment is for a starch test of a leaf.

Explanation:

• When the leaf is placed in boiling water, the high temperature denatures and breaks down the chlorophyll pigment, causing it to lose its green colour.
• The boiling water also softens the leaf and breaks down its cell walls, allowing the alcohol to penetrate more easily.
• The leaf is then immersed in boiling alcohol, which is a solvent that can dissolve the pigments in the leaf.
• The alcohol extracts the chlorophyll that has been denatured by the boiling water.
• The alcohol helps in removing the green colour, turning the leaves white.
• Finally, the leaf is treated with iodine solution, which reacts with starch that is produced by plants during photosynthesis.
• The iodine solution reacts with the starch to produce a blue-black colour.

Hence, the correct answer is option 3.

Concept:

• Osmosis is a special type of diffusion process.
• Osmosis is the process of the movement of a solvent through a semi-permeable membrane from a low solute concentration to a higher solute concentration.
• There are two types of osmosis - Exosmosis and Endosmosis.
• Exosmosis - It involves the migration of the solvent outside the cell. Cells become flaccid during exosmosis.
• Endosmosis - It involves the migration of the solvent inside the cell. Cells become turgid during endosmosis.
• The direction of the flow of water (solvent) in a cell during osmosis is dependent on the type of solution it is placed in.

Important Points

​Hypotonic solution - 

• It refers to a lower osmotic concentration or solute concentration.
• When a cell is placed in a hypotonic solution, the solvent from the solution enters the cell by a process called endosmosis.
• This leads to the swelling of the cell, making the cell turgid.

Hypertonic solution - 

• This refers to a higher osmotic concentration of the solution.
• When a cell is placed in a hypertonic solution, the solvent from the cell moves outside the cell by exosmosis.
• This causes the cell to shrink and become flaccid.

Isotonic solution - 

• This is when the solute concentration of the cell and the solution it is placed in are the same.
• In this case, there is no movement of solvent.
• Thus, there is no change in the diameter of the cells.

In the given case, the RBCs are placed in an isotonic solution, and so there will be no change in size of the RBCs.

Hence, the correct answer is option 4.

Concept:

• Bile is secreted by the hepatic cells of the liver.
• It moves through the hepatic duct into the gall bladder, where it is stored and concentrated.
• It is later secreted into the small intestine along with the pancreatic juice through the common hepato-pancreatic duct.

Important PointsOption 1 - INCORRECT

• The bile is composed of:
• Bile pigments - Bilirubin and biliverdin.
• Bile salts
• Cholesterol
• Phospholipids
• It does not contain any enzyme.

Option 2 - CORRECT

• It helps in emulsification of fats, meaning they help in breakdown of fats into minute micelles.
• Fat digestion is carried out by lipase, which is activated by bile.

Option 3 - CORRECT

• The food is churned in the stomach in acidic medium to form chyme.
• This chyme is neutralized by bile in the duodenum part of small intestine.

Option 4 - CORRECT

• Bile is secreted along with pancreatic juice, which is itself alkaline in nature.
• The alkaline medium is essential in the small intestine for the activities of pancreatic and other enzymes.

Hence, the correct answer is option 1.

Key Points

• Blood pressure refers to the pressure exerted by the blood on the walls of the blood vessels.
• It is generally measured in arteries.
• The instrument used for measuring blood pressure is called a sphygmomanometer.
• Arterial blood pressure refers to the pressure exerted by the blood on the walls of arteries.
• The blood pressure of an individual is normally written as 120/80, which represents SP/DP or systolic pressure/diastolic pressure.
• Blood pressure is calculated during both ventricular contraction and relaxation.
• Systolic Pressure (SP):
• This is the pressure exerted on arterial walls during ventricular contraction.
• Normal SP for a healthy individual is considered to be 120 mmHg.
• Diastolic Pressure (DP):
• The pressure exerted on arterial walls during ventricular relaxation.
• Normal DP for a healthy individual is considered to be 80 mmHg.

Hence, the correct answer is option 1.

Concept:

• To calculate the distance of the cliff from the person, we need to consider the time it took for the sound to travel from the person to the cliff and back as an echo.
• The sound traveled from the person to the cliff, and then the echo traveled back to the person.
• So the total time it took for the sound to travel is twice the time it took to hear the echo.

Calculation:

Given that

The echo was heard 5 seconds after the firecracker burst, we can determine the time it took for the sound to travel from the person to the cliff and back as 5 seconds divided by 2, which is 2.5 seconds.

T = 2.5 sec

Using the formula:

Distance = Speed × Time, we can calculate the distance of the cliff from the person:

Distance = 340 m/s × 2.5 s = 850 meters

Therefore, the distance of the cliff from the person is approximately 850 meters.

The correct answer is option (4)

Explanation:

Statement 1

• This statement is incorrect. The microphone does not convert sound directly to a mechanical signal.
• It typically uses a transducer (such as a condenser or a dynamic element) that converts sound waves into an electrical signal.

Statement 2

• This statement is correct. The primary function of a microphone is to convert sound waves into an electrical signal.
• This electrical signal can then be processed and transmitted through various electronic devices.

Statement 3

• This statement is incorrect. The speaker does not convert a mechanical signal to sound. Instead, it converts an electrical signal into sound waves.
• The electrical signal passes through the speaker's voice coil, which interacts with a magnet, causing the speaker cone to vibrate and produce sound.

Statement 4

• This statement is correct. The speaker converts an electrical signal into sound.
• It receives the electrical signal from the audio source (such as a mobile phone), and through the interaction of the voice coil and the magnet, it generates sound waves that can be heard by the listener.

The correct statements are:

The microphone converts sound to an electrical signal.

The speaker converts an electrical signal to sound.

**The correct answer is option (4)**​

Concept:

Energy

• The rate of doing work is known as energy.
• Energy is the product of power and time.
• The unit of energy is Joule or kWh.

E = P × t

where, E = Energy

P = Power

t = Time

Calculation:

Given,

Rating of each electric bulb(P) = 100 W

Time = 10 hrs per day.

Number of days = 3

So, the total time it work = 3 × 10 = 30 hrs

E = P × t

= 100 × 30

= 3000 Wh

= 3 kWh

= 3 unit

The correct answer is option (1)

Concept:

• The area under the velocity-time graph for a particle moving in a straight line with uniform acceleration gives the net displacement of the particle.
• In physics, displacement refers to the change in position of an object or particle.
• It is a vector quantity that indicates both the magnitude (distance) and direction of the change.
• When a particle undergoes uniform acceleration, its velocity changes at a constant rate.
• The velocity-time graph represents the velocity of the particle as a function of time. The area under this graph, between two specific time points, represents the displacement of the particle during that time interval.

The correct answer is option (2)

Additional Information

• If the velocity-time graph is a straight line segment, the area under the graph is a trapezoid.
• The base of the trapezoid is the time interval, and the height is the average velocity during that interval. The formula for the area of a trapezoid is given by:

Area = (1/2) × (sum of parallel sides) × (height)

In this case, the parallel sides are the initial and final velocities of the particle, and the height is the time interval. Therefore, the area under the velocity-time graph is:

Area = (1/2) × (initial velocity + final velocity) × (time interval)

This area represents the displacement of the particle during the given time interval.

Concept:

Power of Lens:

• The inverse of the focal length is known as the power of the lens.
• It shows the bending strength for the light ray of the lens.
• P is the power of lens and f is the focal length of the lens.

The unit of power of a lens is Dioptre (D) when the focal length of the lens is taken in meter (m).

Calculation:

Given that f = 10 cm = 0.1 m

P = 1 / f = 1 / 0.1 = 10 D

The correct answer is option (3)

All three statements regarding burning of magnesium ribbon in air are correct:

1. When magnesium ribbon burns in air, it reacts with oxygen to form magnesium oxide (MgO), which is a white powder. 2.  Burning of magnesium ribbon is an example of a combustion reaction, where a substance reacts with oxygen to release heat and light.
2. During the burning of magnesium ribbon, heat and light are produced as a result of the exothermic reaction between magnesium and oxygen.

Explanation: 

Combination reaction:

A reaction in which a single product is formed from two or more reactants is known as a combination reaction.

• For example, Calcium oxide( CaO) reacts vigorously with water to produce slaked lime (calcium hydroxide Ca(OH)₂) releasing a large amount of heat as follows;

CaO(s) + H₂O(l) → Ca(OH)₂(aq)

In this reaction, calcium oxide and water combine to form a single

product, calcium hydroxide.

A solution of slaked lime produced by the reaction above is used for white washing walls. Thus, statement (2) is correct and statement

(1) is incorrect.

Calcium hydroxide reacts slowly with the carbon dioxide in air to form a thin layer of calcium carbonate on the walls which is given as follows,

Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s)  ; thus statement (3) is incorrect.

Calcium hydroxide called 'slaked lime' is an inorganic compound is the this statement is correct.

Therefore, the correct answer is option (2) i.e. statement 2 and 4

Explanation:

Decomposition Reaction:

A reaction in which a single reactant breaks down to give simpler products is called as a decomposition reaction.

And when a decomposition reaction is carried out by heating, it is called thermal decomposition.

The decomposition of lead nitrate using heat is an example of thermal decomposition reaction which is as follows;

\(Pb(NO_{3})_{2}(s)\overset{heat}{\rightarrow};PbO(s)+4NO_{2}(g);+O_{2}(g)\)

In the above reaction, brown fumes of NO₂ gas is produced along with colourless oxygen gas.

Therefore, in the correct answer is option (4) i.e. statements 2 and 4 only.

Explanation:

Rusting of iron:

Rusting is an oxidation reaction of iron. Iron reacts with oxygen and water to form rust which is iron oxide.

The process of rusting can be represented by the following equation as follows;

Iron (Fe) + Oxygen (O₂, from the air) + water (H₂O) → rust (iron oxide Fe₂O₃)

For rusting, the presence of both oxygen and water (or water vapour) is essential.

Opening of soda bottle: This is not an oxidation reaction. When a soda bottle is opened, the gas inside is released due to the decrease in pressure. There is no oxidation or reduction of any substance involved in this process.

Rancidity: Rancidity is a type of oxidation reaction that occurs in fats and oils. When fats and oils are exposed to air, the double bonds in the fatty acid molecules react with oxygen in the air to form peroxides, which further break down into aldehydes, ketones, and other compounds. These compounds have a rancid odor and taste.

Combustion: Combustion is a type of oxidation reaction in which a fuel reacts with oxygen to produce heat and light. Examples of combustion reactions include burning of wood, coal, and gasoline.

Therefore, the correct answer is Opening of soda bottle, which is not an oxidation reaction.

The correct answer is Assam.

Key Points

• Assam is often referred to as the "Land of Red River" (Brahmaputra) and "Blue Hills" (referring to the hills of the Eastern Ghats).
• Assam is known for its diverse geographical features and contains three physiographic divisions: the Brahmaputra Valley, the Barak Valley, and the Karbi Anglong and North Cachar Hills.
• Assam covers approximately 2.39 percent of the total geographical area of India.

Additional Information

• India, a country of astonishing diversity, boasts six distinct geographical divisions:
• North Mountain
• Vast plains of India
• Peninsular Plateau
• Coastal Plain
• Island
• Desert

The correct answer is Chhattisgarh, Andhra Pradesh, Karnataka, Maharashtra.

Key Points

• Telangana came into existence as the 29^th state of India on 2 June 2014.
• The Telangana region was part of Hyderabad State from 17 September 1948 to 1 November 1956, until it was merged with Andhra State to form Andhra Pradesh.
• Telangana is surrounded by Maharashtra and Chhattisgarh in the north, Karnataka in the west and Andhra Pradesh in the south and east.

The correct answer is Manipur, Meghalaya, Andhra Pradesh, Tamil Nadu.

Key Points

• Rani mentioned visiting four lakes: Loktak, Barapani, Kolleru, and Pulicat. 
• Loktak - Manipur
• Barapani - Meghalaya
• Kolleru - Andhra Pradesh
• Pulicat - Tamil Nadu
• Therefore, the correct combination of states would be Manipur, Meghalaya, Andhra Pradesh, and Tamil Nadu.

The correct answer is Both 1 and 2.

Key Points

• For the purpose of census 2011, a person aged seven and above,
• Who can both read and write with understanding in any language, is treated as literate. Hence statement 2 is correct.
• A person, who can only read but cannot write, is not literate. Hence statement 1 is correct.
• In the censuses prior to 1991, children below five years of age were necessarily treated as illiterates.

Additional Information

• The results of 2011 census reveal that there has been an increase in literacy in the country.
• The literacy rate in the country is 74.04 per cent, 82.14 for males and 65.46 for females.
• Kerala retained its position by being on top with a 93.91 per cent literacy rate, closely followed by Lakshadweep (92.28 per cent) and Mizoram (91.58 per cent).
• Bihar with a literacy rate of 63.82 per cent ranks last in the country preceded by Arunachal Pradesh (66.95 per cent) and Rajasthan (67.06 per cent).

The correct answer is 2 and 6.

Key Points

• The Tropic of Cancer, an imaginary line of latitude located at 23.5 degrees north of the equator, passes through the following coastal and landlocked states in India:
• Coastal States: The Tropic of Cancer passes through two coastal states in India:
• Gujarat (Jasdan)
• West Bengal (Krishnanagar)
• Landlocked States: The Tropic of Cancer passes through six landlocked states in India:
• Rajasthan (Kalinjarh)
• Madhya Pradesh (Shajapur)
• Chhattisgarh (Sonhat)
• Jharkhand (Lohardaga)
• Tripura (Udaipur)
• Mizoram (Champhai)
• Therefore, it passes through a total of Eight states in India—two coastal states and six landlocked states.

The correct answer is Rapid growth of aggregate demand outweighing supply.

Key Points

• Rapid growth of aggregate demand outweighing supply is a classic scenario that can lead to inflation.
• When demand for goods and services increases at a rate faster than the economy's productive capacity, it puts pressure on resources, and sellers may respond by raising prices.
• This is known as demand-pull inflation, and it is a common explanation for periods of rising prices in an economy.
• Factors such as increased consumer spending, government expenditure, or investment can contribute to a surge in aggregate demand.
• If the supply side of the economy cannot keep pace with this increased demand, inflationary pressures may arise.

Additional Information

• Sluggish growth of aggregate demand can lead to a different economic concern known as deflation, rather than inflation.
• A reduction in the money supply can contribute to deflationary pressure in an economy. When the money supply shrinks, it can lead to a decrease in aggregate demand, less spending, and a possible fall in prices.
• High levels of unemployment can be the result of a variety of economic factors, and are often associated with economic decline or recession.