1. Assertion (A) : Passengers in a boat are not allowed to stand.
Reason (R) : This may raise the centre of gravity of the boat .
Assertion (A) is true: Passengers in a boat are not allowed to stand because it can cause instability.
Reason (R) is true: Standing raises the boat's center of gravity, making it more likely to tip over.
2. Assertion (A) : Telephone wires sag more in summer.
Reason (R) : They expand due to summer heat.
Assertion (A) is true: Telephone wires sag more in summer.
Reason (R) is true: Metals expand when heated due to thermal expansion.
R is not the complete explanation of A. While expansion due to heat causes sagging, the sagging is also influenced by the force of gravity acting on the longer, expanded wire.
3. Assertion (A) : Bronze is used for making statues.
Reason (R) :Bronze is an alloy of copper and tin.
Assertion (A) is true: Bronze is used for making statues.
Reason (R) is true: Bronze is an alloy of copper and tin.
Why is R not the correct explanation?
While it is true that bronze is made of copper and tin, the reason it is used for statues is due to its durability, resistance to corrosion, and ease of casting—not simply because it is an alloy.
Thus, both statements are correct, but R does not fully explain why bronze is used for statues.
4. Assertion (A) : A person with blood group O is considered a universal recipient.
Reason (R) : Type O blood does not contain any antigens.
Blood Group O: It has no antigens on red blood cells but produces anti-A and anti-B antibodies in plasma. Since it lacks A and B antigens, it can be donated to any blood group (O, A, B, AB). That’s why O-negative is called the universal donor for red blood cells.
Blood Group AB: It has both A and B antigens but no antibodies in plasma. This means a person with AB blood can receive blood from any group (O, A, B, AB) without risk of an immune reaction. That’s why AB-positive is called the universal recipient for red blood cells.
However, for plasma transfusions, the roles reverse—AB is the universal plasma donor, and O is the universal plasma recipient.
5. Assertion (A) : Pressure cookers are fitted with ebonite handles.
Reason (R) : Ebonite is strong.
Assertion (A) is true → Pressure cookers are fitted with ebonite handles.
Reason (R) is true → Ebonite is strong.
R is not the correct explanation of A → The main reason for using ebonite handles is that ebonite is a bad conductor of heat, preventing burns when handling the cooker.
6. Assertion (A) : A ship rises as it enters the sea from a river.
Reason (R) : The density of sea water is higher as compared to river water.
A ship rises as it enters the sea from a river because the buoyant force acting on it increases.
This happens because sea water is denser than river water due to dissolved salts.
According to Archimedes' Principle, an object experiences an upward force equal to the weight of the displaced liquid. Since sea water is denser, less volume is needed to displace the same weight, causing the ship to rise.
7. Assertion (A) : Petrol fire cannot be extinguished by pouring water over it.
Reason (R) : Water is heavier than petrol.
Water is heavier than petrol, so it sinks while petrol floats and keeps burning. Instead of water, sand or foam should be used to put out petrol fires.
8. Assertion (A) : Safety fuses are made up of materials having a high melting point.
Reason (R) : Safety fuses should be resistant to electric current.
Assertion (A) is false because safety fuses are made of materials with a low melting point (like tin-lead alloy) so that they melt and break the circuit when excessive current flows.
Reason (R) is also false because safety fuses are not resistant to electric current; instead, they are designed to allow current to pass but melt under excessive current flow to prevent damage.
9. Assertion (A) : Leaves of plants are green.
Reason (R) : Plants contain chromoplasts, the green pigment.
Assertion (A) is true because leaves of plants are green.
Reason (R) is false because the green pigment in plants is chlorophyll, which is found in chloroplasts, not chromoplasts. Chromoplasts contain pigments like carotenoids that give red, yellow, and orange colors.
10. Assertion (A) : Beri-beri is a viral infection.
Reason (R) : Vitamin deficiency causes diseases.
Beri-beri is not a viral infection; it is a disease caused by vitamin B1 (thiamine) deficiency. So, Assertion (A) is false.
Vitamin deficiencies do cause diseases (e.g., scurvy due to vitamin C deficiency, rickets due to vitamin D deficiency). So, Reason (R) is true.
11. Assertion (A) : Diamond is used for cutting glass.
Reason (R) : Diamond has a high refractive index.
A (True): Diamond is used for cutting glass.
R (True): Diamond has a high refractive index.
But: Diamond cuts glass due to its hardness, not because of its refractive index.
Correct Answer: (A) Both A and R are true, but R is not the correct explanation of A.
12. Assertion (A) : Tamil Nadu gets most of the rainfall in winter.
Reason (R) : Tamil Nadu gets rainfall from retreating monsoons.
Tamil Nadu receives most of its rainfall in winter due to the retreating monsoons (Northeast Monsoon), which occur from October to December
13. Assertion (A) : Bangladesh imports jute from India.
Reason (R) : Bangladesh has most of the jute mills.
Assertion (A) is false: Bangladesh does not import jute from India; rather, India imports raw jute from Bangladesh because most jute-growing areas went to Bangladesh after partition.
Reason (R) is false: Bangladesh does not have most of the jute mills; instead, the majority of jute mills remained in India (mainly in West Bengal) after partition.
14. Assertion (A) : Indian President is the head of the state.
Reason (R) : Indian Parliament consists of the President, Lok Sabha and Rajya Sabha.
Assertion (A) is true: The President of India is the head of the state, but only in a constitutional or titular capacity. The real executive power rests with the Council of Ministers, headed by the Prime Minister (Article 53).
Reason (R) is true: The Indian Parliament consists of the President, Lok Sabha, and Rajya Sabha (Article 79).
R does not explain A: The President is the head of state not because they are part of Parliament but because the Constitution designates them as such.
15. Assertion (A) : Uranium undergoes nuclear fusion reaction.
Reason (R) : It has a big, unstable nucleus.
Assertion (A) is false because uranium undergoes nuclear fission, not nuclear fusion. In fission, the uranium nucleus splits into smaller nuclei, releasing energy.
Reason (R) is true because uranium has a large, unstable nucleus, which makes it suitable for nuclear fission.
16. Assertion (A) : Goitre is a common disease in mountainous regions.
Reason (R) : The diet of the people in mountains lacks iodine content.
Assertion (A) is true: Goitre is common in mountainous regions due to iodine deficiency.
Reason (R) is true: People in mountainous regions often lack iodine in their diet because iodine-rich seafood is less available, and the soil in these regions is iodine-deficient.
R correctly explains A: Iodine deficiency leads to an underactive thyroid gland, causing goitre.
Thus, both A and R are true, and R correctly explains A.
17. Assertion (A) : We feel colder on mountains than on plains.
Reason (R) : Temperature decreases with altitudes.
Assertion (A) is true: We feel colder on mountains than on plains.
Reason (R) is true: Temperature decreases with altitude (known as the lapse rate, where temperature drops by about 6.5°C per 1,000 meters).
R correctly explains A: The higher we go, the lower the temperature, which explains why mountains are colder than plains.
18. Assertion (A) :Sprouting should not done before consuming the grains.
Reason (R) : Sprouting kills many vital vitamins.
Assertion (A) is false: Sprouting is actually beneficial as it enhances the nutritional value of grains by increasing vitamin and mineral content.
Reason (R) is false: Sprouting does not kill vitamins; instead, it boosts vitamin levels, especially Vitamin C and B-complex vitamins.
19. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Amoebiasis is an occupational disease.
Reason (R) : Amoebiasis is caused by inhalation of asbestos duet.
Assertion (A) is false: Amoebiasis is not an occupational disease; it is an infectious disease caused by Entamoeba histolytica, which spreads through contaminated food and water.
Reason (R) is false: Amoebiasis is not caused by inhalation of asbestos dust; asbestos exposure leads to diseases like asbestosis and lung cancer, not amoebiasis.
20. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : The Indian Constitution came into force with effect from 26th January, 1950
Reason (R) : 26th January is celebrated as the Republic
Assertion (A) is true: The Indian Constitution came into force on 26th January 1950, officially making India a sovereign democratic republic.
Reason (R) is true: 26th January is celebrated as Republic Day to mark this historic event.
R correctly explains A: The date 26th January was chosen to honor the Purna Swaraj resolution passed on 26th January 1930 by the Indian National Congress, which had declared the demand for complete independence from British rule.
21. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Akbar founded Din-e-Ilahi.
Reason (R) : He was motivated by self glorification.
Assertion (A) is true: Akbar founded Din-e-Ilahi in 1582 as a syncretic religious movement aimed at promoting harmony among different faiths.
Reason (R) is false: Akbar was not motivated by self-glorification but by his vision of religious tolerance and unity among his diverse subjects.
22. Assertion (A) : Downpour of rain lessens the humidity in the atmosphere.
Reason (R) : Rains are caused when atmosphere cannot hold more moisture.
Assertion (A) is false: A downpour of rain actually increases humidity near the Earth's surface due to evaporation after rainfall.
Reason (R) is true: Rains occur when the upper atmosphere becomes saturated and cannot hold more moisture, leading to condensation and precipitation.
23. Assertion (A) : Red green colour blindness occurs with more frequency in males than in females.
Reason (R) : Females have two chromosomes and males have one.
Since color blindness is an X-linked recessive trait, males (XY) are more likely to be affected because they have only one X chromosome. If that X chromosome carries the defective gene, there is no second X to compensate.
Females (XX) are less likely to be colorblind because they would need both X chromosomes to have the defective gene. If only one X has the defective gene, the other normal X compensates, making them carriers instead of affected individuals.
24. Assertion (A) : Cotton is grown in alluvial soils.
Reason (R) : Alluvial soils are very fertile.
Cotton is primarily grown in black soil (also called Regur soil), which is rich in clay, moisture-retentive, and well-suited for cotton cultivation.
Alluvial soils are very fertile but are more suited for crops like rice, wheat, and sugarcane rather than cotton.
Thus, Assertion (A) is false, but Reason (R) is true
25. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Bulb filament is made of titanium.
Reason (R) : The filament should have low melting point.
Bulb filaments are made of tungsten, not titanium. Tungsten has a very high melting point (~3422°C), which makes it ideal for use in light bulbs.
The filament should have a high melting point, not a low melting point, so that it can glow without melting.
Since both the assertion and reason are incorrect, the correct answer is (D).
26. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Gandhiji withdrew the non cooperation movement.
Reason (R) : There was violence at the Chauri Chaura outrage.
Assertion (A) is true: Mahatma Gandhi withdrew the Non-Cooperation Movement in 1922.
Reason (R) is also true: The movement was called off after the Chauri Chaura incident (February 5, 1922), where a violent mob set fire to a police station, killing 22 policemen.
Since Gandhi believed in non-violence (Ahimsa), he decided to withdraw the movement to prevent further violence.
27. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : A little gap is left between iron rails.
Reason (R) : Iron expands in summer.
Assertion (A) is true: A small gap is left between iron railway tracks to prevent damage.
Reason (R) is true: Iron expands when heated, especially during summer.
Correct Explanation: The gap allows the iron to expand without bending or breaking the rails due to thermal expansion.
28. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Carbon dioxide turns lime water milky.
Reason (R) : Carbon dioxide sullies the water.
Assertion (A) is true: Carbon dioxide turns lime water (Ca(OH)₂ solution) milky due to the formation of calcium carbonate Ca(OH)₂ +CO₂ →CaCO₃↓(whiteprecipitate)+H₂O
Reason (R) is false: The term "sullies the water" is incorrect. CO₂ does not make water dirty; it reacts with lime water to form an insoluble precipitate (CaCO₃), causing the milky appearance.
29. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Carbon forms the largest number of compounds.
Reason (R) : Carbon has the catenation property.
Carbon has the highest catenation property due to the strong C-C single bond and its ability to form four covalent bonds. This property allows carbon to form long chains, branched structures, and rings, leading to the formation of a vast number of organic compounds.
This is why carbon is considered the building block of life and why organic chemistry revolves around carbon-based compounds.
30. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Buddha left home after his marriage.
Reason (R) : He wished to be free of all worldly ties and become an ascetic.
Assertion (A) is true: Gautama Buddha left his home after marriage.
Reason (R) is true and explains A: He wished to be free from worldly ties and seek enlightenment, which led him to renounce his princely life and become an ascetic.
31. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Moon cannot be used as a satellite for communication. Reason (R) : Moon does not move in the equatorial plane of the earth.
The Moon cannot be used as a communication satellite because it does not follow a geostationary or equatorial orbit around the Earth.
Communication satellites need to be in a stable orbit, usually in the geostationary equatorial orbit (GEO), so that they remain fixed relative to a point on Earth.
The Moon moves in an elliptical orbit inclined to the Earth's equatorial plane, making it unsuitable for continuous communication.
32. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): When a body is dipped in a liquid fully or partially, there is a decrease in its weight.
Reason (R) : The decrease in weight is due t
When a body is dipped in a liquid, it experiences an upward buoyant force equal to the weight of the displaced liquid, reducing its apparent weight.
The decrease in weight is due to buoyant force, not just the liquid’s density. Thus, the assertion is true, but the reason is false.
33. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): River Narmada flows westward.
Reason (R) : Narmada falls into the Bay of Bengal.
Assertion (A) is true – River Narmada flows westward.
Reason (R) is false – Narmada falls into the Arabian Sea, not the Bay of Bengal.
34. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): No food material normally enters the wind pipe during swallowing.
Reason (R) : When we swallow, the back portion of our tongue covers
Both the assertion (A) and reason (R) are true, and R correctly explains A. Normally, food does not enter the windpipe during swallowing because a protective mechanism prevents it.
The epiglottis, a flap-like structure, covers the glottis (opening of the windpipe) to direct food towards the esophagus.
The back portion of the tongue also assists in sealing the airway, ensuring food does not enter the trachea.
This mechanism prevents choking and ensures safe swallowing. Without this process, food could enter the lungs, causing aspiration.
The coordination of the tongue and epiglottis is vital for proper digestion and respiration.
35. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Land breeze blows during night.
Reason (R) : Land gets heated up quickly.
Land gets heated up quickly and also cools quicker than sea at night so that cool winds called the land breeze blow from land to sea.
36. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : There is rainbow in the sky only after rains.
Reason (R) : Water drops suspended in the air break up sun’s rays into seven colours.
Water droplets act like prisms. Sun’s rays falling on water droplets suffer dispersion and produce a spectrum.
37. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : In India, people elect their own representative.
Reason (R) : India is a democracy.
In India, people elect their own representatives through a democratic process, such as general elections for the Lok Sabha and state assemblies.
India follows a democratic system where the government is elected by the people, ensuring representation in decision-making.
Democracy means a government "of the people, by the people, for the people," which directly explains why citizens have the right to vote and choose their representatives.
38. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Winds are deflected to their right in Northern Hemisphere and to the left in the Southern Hemisphere.
Reason (R) : Rotation of earth
The Coriolis Effect, caused by the rotation of the Earth, is responsible for the deflection of winds.
In the Northern Hemisphere, winds are deflected to the right, while in the Southern Hemisphere, they are deflected to the left.
This effect influences global wind patterns, ocean currents, and even weather systems. Since the Earth's rotation causes this deflection, the Reason (R) correctly explains the Assertion (A).
39. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A) : Leakages in household gas cylinders can be detected.
Reason (R) : LPG has a strong smell.
LPG (Liquefied Petroleum Gas) is naturally odorless, but a strong-smelling compound called Ethyl Mercaptan is added to it.
This distinct smell helps in detecting gas leaks quickly, preventing potential hazards like fire or explosions. Since the strong smell of LPG enables leak detection, Reason (R) correctly explains Assertion (A).
40. In each of the questions given below, there are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): Bats can fly in the night.
Reason (R) : Bats emit ultrasonics.
Assertion (A) is true: Bats can fly at night.
Reason (R) is true: Bats emit ultrasonic sounds to detect obstacles and prey.
R correctly explains A: Their ability to fly safely at night is due to echolocation, which helps them perceive their surroundings in the absence of light.