Science plays a key role in every competitive exam, from CSS and PMS to FPSC, UPSC, and one-paper tests. After covering the first 100 MCQs, this is the second set MCQs of our Everyday Science MCQs with detailed explanations.
Unlike short guides that only give direct answers, we provide step-by-step reasoning behind each question. This ensures that students don’t just memorize facts but actually understand the concept.
Whether it’s about physics, chemistry, biology, environmental science, or daily life applications of science, these MCQs will sharpen your preparation and help you score higher in exams.
1. The soul of chemistry is dealing with___________?
A) Internal structural changes in matter
B) Composition of matter
C) Properties of matter
D) Composition and properties of matter ✅
Correct Answer: D) Composition and properties of matter
Explanation:
Chemistry is the branch of science that studies the composition, structure, properties, and changes of matter. It explains how substances interact, combine, and change to form new substances. Since it covers both composition (what matter is made of) and properties (how it behaves), the most accurate option is D.
2. Which one is the most common disease?
A) Dental
B) Leprosy
C) Headache ✅
D) Migraine
Correct Answer: C) Headache
Explanation:
A headache is one of the most common medical complaints worldwide. While dental issues and migraines are frequent, a general headache is the most widespread condition affecting people of all ages. According to WHO, almost 50% of adults suffer from headaches every year.
3. Orange belongs to the family:
A) Malvaceae
B) Rosaceae
C) Rutaceae ✅
D) Composite
Correct Answer: C) Rutaceae
Explanation:
Orange and other citrus fruits (lemon, lime, grapefruit) belong to the Rutaceae family. This family is well-known for aromatic plants rich in essential oils and Vitamin C.
4. Vertebral column in human beings consists of how many vertebrae?
A) 5
B) 10
C) 12
D) 33 ✅
Correct Answer: D) 33
Explanation:
The human vertebral column (spine) has 33 vertebrae, divided into:
5. 2017 Nobel Prize in Physics was awarded for:
A) Far Observation of Gravitational Waves
B) Far Observation of Gravitational Weight
C) First Observation of Gravitational Waves ✅
D) Far Objectivity of Gravitational Waves
Correct Answer: C) First Observation of Gravitational Waves
Explanation:
The 2017 Nobel Prize in Physics was awarded to Rainer Weiss, Barry C. Barish, and Kip S. Thorne for their contribution to the LIGO detector and the first direct observation of gravitational waves (ripples in space-time predicted by Einstein’s General Relativity).
6. Diesel engine was discovered by___________?
A) Paul Muller
B) Faraday
C) Waldeyer
D) Rudolf Diesel ✅
Correct Answer: D) Rudolf Diesel
Explanation:
The diesel engine was invented by Rudolf Diesel in 1892. It works on the principle of compression ignition, where air is compressed to a high temperature, and fuel is then injected to ignite.
7. Electron was discovered by?
A) Michael Faraday
B) James Maxwell
C) Yuri Gagarin
D) J.J. Thomson ✅
Correct Answer: D) J.J. Thomson
Explanation:
The electron was discovered in 1897 by J.J. Thomson using the cathode ray tube experiment. This discovery proved that atoms are divisible and contain smaller charged particles.
8. Which planet is much brighter in our solar system?
A) Earth
B) Venus ✅
C) Mercury
D) Jupiter
Correct Answer: B) Venus
Explanation:
Venus is called the “Morning Star” or “Evening Star” because it is the brightest planet visible from Earth. Its dense atmosphere reflects sunlight effectively, making it shine brighter than other planets.
9. The main function of kidney is____________?
A) To control blood pressure
B) To control body temperature
C) To remove waste from blood ✅
D) To help in digestion of body
Correct Answer: C) To remove waste from blood
Explanation:
The kidneys act as the body’s natural filter, removing waste products, toxins, and excess water from the blood in the form of urine. They also help regulate blood pressure, red blood cell production, and electrolyte balance.
10. The energy stored in a dam is___________?
A) Kinetic energy
B) Electrical energy
C) Potential energy ✅
D) None of these
Correct Answer: C) Potential energy
Explanation:
Water stored in a dam at a height has potential energy due to gravity. When released, it flows down and converts into kinetic energy, which is then converted into electrical energy by turbines in a hydropower plant.
11. An iceberg is floating in sea. How much of its mass will remain above the surface of water?
A. One tenth
B. One fifth
C. One fourth
D. One third ✅
Explanation:
Ice is less dense than liquid water, which is why icebergs float. However, about 90% of the iceberg’s mass remains submerged while only 1/10th stays above the surface. This phenomenon is due to the principle of buoyancy explained by Archimedes. The popular saying “tip of the iceberg” comes from this fact.
12. Most of the ozone in the atmosphere is concentrated in the _____________?
A. Mesosphere
B. Troposphere
C. Stratosphere ✅
D. Ionosphere
Explanation:
The ozone layer lies in the lower part of the stratosphere (15–35 km above Earth). It absorbs harmful ultraviolet (UV) radiation from the sun, protecting living organisms. Without this shield, UV rays could cause severe health and environmental damage.
13. The cow’s milk contains how much amount of water in terms of percentage?
A. 60%
B. 65%
C. 72% ✅
D. 80%
Explanation:
Cow’s milk is about 72% water and 28% solids (fats, proteins, lactose, and minerals). This high-water content makes it a balanced natural drink and an essential dietary source of calcium and vitamins.
14. T.V. transmission cannot cover a very large area because __________?
A. The strength of T.V. waves is very limited
B. Picture cannot be transmitted clearly after a distance
C. The shape of the earth is spherical ✅
D. The air is not a good conductor of waves
Explanation:
Television transmission uses line-of-sight signals that travel in straight lines. Since the Earth is curved, TV waves cannot cover beyond the horizon. That’s why relay stations, satellites, and cable networks are needed for long-distance broadcasting.
15. The Greenhouse Effect is caused by an excess of __________?
A. Carbon dioxide ✅
B. Carbon monoxide
C. Carbon tetrachloride
D. None of the above
Explanation:
The greenhouse effect occurs when gases like carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) trap heat in Earth’s atmosphere. CO₂ is the main culprit, rising due to fossil fuel burning and deforestation. This leads to global warming and climate change.
16. Bats can also fly in dark because they are capable of taking the help of __________?
A. Ultraviolet Waves
B. Ultrasonic Waves ✅
C. Electromagnetic Waves
D. Special Retina
Explanation:
Bats use echolocation by emitting ultrasonic waves (high-frequency sounds). The reflected waves help them detect objects, prey, and navigate even in complete darkness. This natural sonar system is more effective than human vision at night.
17. What is ‘Stealth Technology’?
A. A device which when attached to an aircraft makes it invisible on the radar ✅
B. A coating which reduces radar visibility
C. A technology to spy in enemy air-space
D. A technology for paratroopers
Explanation:
Stealth technology reduces the detection of aircraft, ships, or missiles by radar, infrared, and sonar. It works by using special materials, coatings, and shapes that minimize reflection. Famous examples include the B-2 Spirit stealth bomber and F-117 Nighthawk.
18. The primary function of the feathers in birds is to __________?
A. Provide insulation for preserving body heat
B. Provide striking surface to the wings for flying ✅
C. Make the body surface waterproof
D. Impart coloration for species recognition
Explanation:
Feathers serve multiple purposes, but their main function is enabling flight. The structure of wing feathers allows birds to generate lift and thrust. They also provide insulation, waterproofing, and camouflage, but flight remains the primary role.
19. The rear-view mirror of a motor vehicle is __________?
A. Concave
B. Plane
C. Convex ✅
D. Biconcave
Explanation:
Rear-view mirrors are convex mirrors because they provide a wider field of view, allowing drivers to see more area behind the vehicle. However, they make objects appear smaller and farther away than they really are.
20. Lead ball falls through water more slowly than through air because __________?
A. The value of ‘g’ is less in water
B. Density of air is less than that of water
C. Of the viscous force in water ✅
D. Of surface tension of water
Explanation:
When a lead ball falls in water, viscous force (fluid resistance) slows its motion. In air, viscosity is negligible, so objects fall faster. The principle is explained by Stokes’ Law in fluid dynamics.
21. A fountain pen works on the principle of __________?
A. Capillarity
B. Viscosity
C. Boyle’s law
D. Atmospheric pressure ✅
Explanation:
The ink in a fountain pen flows because of atmospheric pressure. When we press the nib on paper, the air pressure on the ink reservoir forces the ink downward. Capillary action helps spread ink on the paper, but the main principle is air pressure.
22. The speed of light will be minimum while passing through __________?
A. Vacuum
B. Water
C. Air
D. Glass ✅
Explanation:
Light travels fastest in vacuum and slows down in denser mediums. Glass has a higher refractive index than air or water, so light slows down the most in glass. This bending of light is why lenses work in spectacles and cameras.
23. A body can escape the gravitational pull of the Earth if it is thrown up with a velocity of __________?
A. 25 km/sec
B. 15 km/sec
C. 10 km/sec
D. 11.2 km/sec ✅
Explanation:
The escape velocity of Earth is 11.2 km/sec. It’s the minimum speed an object needs to break free from Earth’s gravitational field without any further propulsion. Rockets achieve this speed to enter outer space.
24. An artificial satellite revolves around the Earth in which path?
A. Circular
B. Elliptical
C. Both (A) and (B) ✅
D. Parabolic
Explanation:
Artificial satellites can revolve in circular or elliptical orbits depending on their purpose. Communication satellites usually follow geostationary circular orbits, while scientific satellites often use elliptical paths for broader coverage.
25. The instrument used to measure blood pressure is __________?
A. Stethoscope
B. Hygrometer
C. Sphygmomanometer ✅
D. Thermometer
Explanation:
Blood pressure is measured using a sphygmomanometer, often with a stethoscope. It records systolic (heart contraction) and diastolic (heart relaxation) pressures. The normal value is 120/80 mmHg for a healthy adult.
26. Which gas is used in balloons to make them fly high?
A. Oxygen
B. Hydrogen
C. Nitrogen
D. Helium ✅
Explanation:
Helium is lighter than air and non-flammable, making it the safest gas for balloons. Earlier, hydrogen was used but it is highly explosive, which caused accidents like the Hindenburg disaster (1937).
27. The hardest natural substance on Earth is __________?
A. Gold
B. Iron
C. Quartz
D. Diamond ✅
Explanation:
Diamond is the hardest naturally occurring material due to its strong carbon-carbon covalent bonds in a crystal lattice. It ranks 10 on the Mohs hardness scale, making it useful for cutting, drilling, and jewelry.
28. Deficiency of Vitamin C leads to __________?
A. Rickets
B. Night blindness
C. Scurvy ✅
D. Beriberi
Explanation:
Vitamin C deficiency causes scurvy, characterized by bleeding gums, joint pain, and weakness. Vitamin C is vital for collagen production and immunity. Citrus fruits, guava, and green vegetables are rich sources.
29. Sound travels fastest in __________?
A. Air
B. Water
C. Gases
D. Solids ✅
Explanation:
Sound travels fastest in solids because particles are tightly packed, allowing vibrations to transfer more quickly. It travels slower in liquids and slowest in gases. For example, sound in steel is much faster than in air.
30. Which part of the human brain controls balance and posture?
A. Cerebrum
B. Cerebellum ✅
C. Medulla oblongata
D. Thalamus
Explanation:
The cerebellum at the back of the brain regulates balance, posture, and coordination of voluntary movements. Damage to it can cause loss of balance, tremors, and difficulty walking.
31. Which planet is known as the “Red Planet”?
A. Venus
B. Jupiter
C. Mars ✅
D. Mercury
Explanation:
Mars appears red because its surface contains iron oxide (rust), giving it a reddish color. Scientists are particularly interested in Mars for exploration as it has signs of water and potential habitability.
32. The chemical formula of common salt is __________?
A. KCl
B. NaCl ✅
C. Na2CO3
D. NaOH
Explanation:
Common salt is sodium chloride (NaCl). It’s essential for human survival, maintaining fluid balance, nerve function, and muscle contraction. It also preserves food.
33. Who is known as the “Father of Genetics”?
A. Charles Darwin
B. Louis Pasteur
C. Gregor Mendel ✅
D. Robert Hooke
Explanation:
Gregor Mendel, through his experiments on pea plants, discovered the fundamental laws of heredity: dominance, segregation, and independent assortment. His work laid the foundation of modern genetics.
34. The ozone layer protects life on Earth by absorbing __________?
A. Infrared rays
B. Ultraviolet rays ✅
C. Visible light
D. X-rays
Explanation:
The ozone layer, located in the stratosphere, absorbs harmful UV-B radiation from the sun. Without this shield, living organisms would face severe risks like skin cancer, cataracts, and reduced crop yields.
35. The SI unit of electric current is __________?
A. Volt
B. Ohm
C. Ampere ✅
D. Watt
Explanation:
The ampere (A) is the SI unit of electric current. One ampere equals the flow of one coulomb of charge per second. It’s a fundamental electrical unit, along with volt (potential difference) and ohm (resistance).
36. The first man-made satellite launched in space was __________?
A. Apollo 11
B. Sputnik 1 ✅
C. Voyager 1
D. Explorer 1
Explanation:
Sputnik 1 was launched by the Soviet Union in 1957, marking the beginning of the space age. It orbited Earth and shocked the world, leading to the US–USSR space race.
37. Which blood group is called the “Universal Donor”?
A. AB+
B. AB-
C. O- ✅
D. O+
Explanation:
People with O-negative blood can donate to almost all other blood groups because it lacks A, B, and Rh antigens. However, O- individuals can only receive O- blood.
38. Photosynthesis mainly takes place in which part of a plant?
A. Roots
B. Flowers
C. Leaves ✅
D. Stem
Explanation:
Leaves contain chloroplasts filled with chlorophyll, which captures sunlight to produce glucose and oxygen from carbon dioxide and water. This process is the basis of life on Earth’s food chain.
39. Which metal is liquid at room temperature?
A. Sodium
B. Aluminum
C. Potassium
D. Mercury ✅
Explanation:
Mercury (Hg) is the only metal liquid at room temperature. It expands uniformly with heat, making it ideal for thermometers. However, it’s highly toxic and now being replaced by safer alternatives.
40. Which part of the human eye controls the amount of light entering it?
A. Lens
B. Retina
C. Iris ✅
D. Cornea
Explanation:
The iris is the colored part of the eye that adjusts the size of the pupil to control light entry. In bright light, the pupil contracts, and in darkness, it dilates to allow more light.
41. Which gas is essential for human respiration?
A. Carbon dioxide
B. Nitrogen
C. Oxygen ✅
D. Hydrogen
Explanation:
Humans need oxygen (O₂) to survive. It helps break down glucose in cells to release energy (ATP) during cellular respiration. Without oxygen, brain damage can occur within minutes.
42. What is the boiling point of water at sea level?
A. 90°C
B. 95°C
C. 100°C ✅
D. 110°C
Explanation:
At 1 atmosphere pressure (sea level), water boils at 100°C. At higher altitudes, atmospheric pressure is lower, so water boils at a lower temperature.
43. Who discovered penicillin, the first true antibiotic?
A. Louis Pasteur
B. Robert Koch
C. Alexander Fleming ✅
D. Joseph Lister
Explanation:
In 1928, Alexander Fleming discovered penicillin from the Penicillium mold. This revolutionized medicine by enabling treatment of bacterial infections, saving millions of lives.
44. Which vitamin is produced in the skin with the help of sunlight?
A. Vitamin A
B. Vitamin D ✅
C. Vitamin B12
D. Vitamin C
Explanation:
When exposed to sunlight, the skin synthesizes Vitamin D. It strengthens bones and teeth by regulating calcium and phosphorus absorption. Deficiency can cause rickets in children.
45. The largest gland in the human body is __________?
A. Pancreas
B. Thyroid
C. Liver ✅
D. Pituitary
Explanation:
The liver is the largest gland. It produces bile, stores glycogen, detoxifies harmful substances, and regulates metabolism. It’s vital for digestion and overall health.
46. Which gas is commonly known as “laughing gas”?
A. Carbon monoxide
B. Nitric oxide
C. Nitrous oxide ✅
D. Methane
Explanation:
Nitrous oxide (N₂O) is called laughing gas because inhaling it causes mild euphoria and laughter. It’s used in anesthesia and dentistry for pain relief.
47. What is the normal pH of human blood?
A. 6.8
B. 7.4 ✅
C. 8.0
D. 7.0
Explanation:
The normal blood pH is 7.35–7.45. It’s slightly alkaline. Any major deviation can be life-threatening, as enzymes and cells require a stable pH to function.
48. Which of the following is a renewable source of energy?
A. Coal
B. Solar energy ✅
C. Petroleum
D. Natural gas
Explanation:
Solar energy is renewable because sunlight is abundant and inexhaustible. In contrast, coal, petroleum, and natural gas are fossil fuels that deplete and pollute.
49. Who is known as the “Father of Modern Physics”?
A. Galileo Galilei
B. Albert Einstein ✅
C. Isaac Newton
D. Niels Bohr
Explanation:
While Newton laid the foundation of classical physics, Albert Einstein revolutionized science with theory of relativity and contributions to quantum mechanics, earning the title “Father of Modern Physics.”
50. The hardest natural substance on Earth is __________?
A. Quartz
B. Iron
C. Gold
D. Diamond ✅
Explanation:
Diamond, made of pure carbon atoms arranged in a strong lattice, is the hardest natural material. It’s used in jewelry and industrial tools like drills and cutters.
51. Which part of the plant carries out photosynthesis?
A. Root
B. Stem
C. Leaf ✅
D. Flower
Explanation:
Leaves contain chlorophyll, a green pigment that captures sunlight. Through photosynthesis, plants convert carbon dioxide + water → glucose + oxygen, providing food and oxygen for life on Earth.
52. Which is the fastest land animal?
A. Horse
B. Lion
C. Cheetah ✅
D. Tiger
Explanation:
The cheetah can run up to 110 km/h (70 mph) in short bursts. It is adapted with long limbs, strong muscles, and large nasal passages for oxygen intake.
53. What is the main function of the ozone layer?
A. Traps heat
B. Produces oxygen
C. Blocks harmful UV rays ✅
D. Absorbs carbon dioxide
Explanation:
The ozone layer, located in the stratosphere, protects life on Earth by absorbing harmful ultraviolet (UV) radiation from the sun. Without it, skin cancer rates and crop damage would rise.
54. Which blood group is known as the universal donor?
A. AB+
B. AB−
C. O+
D. O− ✅
Explanation:
O-negative blood lacks A, B, and Rh antigens, so it can be given to patients of any blood type. This makes O− donors highly valuable in emergencies.
55. Which element is essential for the formation of hemoglobin in blood?
A. Calcium
B. Potassium
C. Iron ✅
D. Sodium
Explanation:
Hemoglobin is a protein in red blood cells that carries oxygen. Its red color comes from iron, which binds to oxygen. Iron deficiency leads to anemia.
56. The study of earthquakes is called:
A. Geology
B. Volcanology
C. Seismology ✅
D. Geophysics
Explanation:
Seismology is the branch of earth science that studies earthquakes and seismic waves. Instruments called seismographs record vibrations of the Earth.
57. Which gas causes the greenhouse effect the most?
A. Oxygen
B. Nitrogen
C. Carbon dioxide ✅
D. Hydrogen
Explanation:
Carbon dioxide (CO₂) traps heat in Earth’s atmosphere, contributing to global warming. Other greenhouse gases include methane (CH₄) and nitrous oxide (N₂O), but CO₂ is the main contributor.
58. Which is the heaviest naturally occurring element?
A. Uranium
B. Lead
C. Gold
D. Plutonium ✅
Explanation:
Among naturally occurring elements, uranium is the heaviest with atomic number 92. Plutonium is mostly artificial, but uranium is more stable and widely used in nuclear fuel. (Correct answer: Uranium) ✅
59. Which scientist proposed the three laws of motion?
A. Albert Einstein
B. Isaac Newton ✅
C. Galileo Galilei
D. Johannes Kepler
Explanation:
In 1687, Sir Isaac Newton introduced the laws of motion in Principia Mathematica. These laws form the foundation of classical mechanics and explain how objects move under forces.
60. What is the approximate age of the Earth?
A. 2 billion years
B. 3 billion years
C. 4.5 billion years ✅
D. 6 billion years
Explanation:
Scientific evidence from radiometric dating of rocks and meteorites shows Earth is about 4.5 billion years old. This makes it almost as old as the solar system.
61. Which organ in the human body produces insulin?
A. Liver
B. Kidney
C. Pancreas ✅
D. Stomach
Explanation:
The pancreas produces insulin, a hormone that regulates blood sugar by helping cells absorb glucose. Lack of insulin causes diabetes mellitus.
62. Which planet is known as the “Morning Star” or “Evening Star”?
A. Mercury
B. Venus ✅
C. Mars
D. Jupiter
Explanation:
Venus is the brightest planet in the night sky, visible just before sunrise or after sunset. Its thick CO₂ atmosphere causes a strong greenhouse effect, making it the hottest planet.
63. The hardest natural substance on Earth is:
A. Gold
B. Iron
C. Diamond ✅
D. Quartz
Explanation:
Diamond, made of pure carbon atoms arranged in a crystal lattice, is the hardest known natural material. It is used in jewelry and cutting tools.
64. Which vitamin is produced in the skin when exposed to sunlight?
A. Vitamin A
B. Vitamin B
C. Vitamin D ✅
D. Vitamin K
Explanation:
When skin is exposed to UV rays, it synthesizes Vitamin D, essential for calcium absorption and bone health. Deficiency causes rickets in children.
65. What is the speed of light in vacuum?
A. 150,000 km/s
B. 200,000 km/s
C. 300,000 km/s ✅
D. 350,000 km/s
Explanation:
The speed of light in vacuum is approximately 299,792 km/s (≈ 300,000 km/s). It is the universal speed limit according to Einstein’s relativity theory.
66. Which is the most abundant gas in Earth’s atmosphere?
A. Oxygen
B. Carbon dioxide
C. Argon
D. Nitrogen ✅
Explanation:
About 78% of Earth’s atmosphere is nitrogen, followed by 21% oxygen and small amounts of argon, CO₂, and other gases.
67. The scientific study of insects is called:
A. Zoology
B. Botany
C. Entomology ✅
D. Ecology
Explanation:
Entomology is the branch of zoology dealing with insects, which make up more than 75% of all known animal species.
68. Which disease is caused by the deficiency of Vitamin C?
A. Rickets
B. Night blindness
C. Scurvy ✅
D. Beriberi
Explanation:
Scurvy is caused by Vitamin C deficiency. Symptoms include bleeding gums, weakness, and delayed wound healing. Sailors in the past often suffered from it.
69. The chemical formula of common salt is:
A. KCl
B. NaCl ✅
C. HCl
D. CaCl₂
Explanation:
Common salt is chemically sodium chloride (NaCl). It is essential for nerve function and maintaining fluid balance in the human body.
70. Which scientist discovered penicillin?
A. Louis Pasteur
B. Robert Koch
C. Alexander Fleming ✅
D. Edward Jenner
Explanation:
In 1928, Alexander Fleming discovered penicillin, the world’s first antibiotic. It revolutionized medicine by saving millions of lives from bacterial infections.
71. The blue color of the sky is due to:
A. Reflection of sunlight
B. Refraction of sunlight
C. Scattering of light ✅
D. Diffusion of gases
Explanation:
The blue color of the sky is caused by Rayleigh scattering. Shorter wavelengths (blue light) scatter more than longer wavelengths (red), making the sky appear blue.
72. The unit of electric current is:
A. Volt
B. Watt
C. Ampere ✅
D. Ohm
Explanation:
The ampere (A) is the SI unit of electric current. It measures the flow of electric charge per second through a conductor.
73. Which blood group is known as the universal donor?
A. AB+
B. AB–
C. O+
D. O– ✅
Explanation:
O negative (O–) blood is called the universal donor, as it can be transfused to patients of all blood types.
74. Which gas is commonly used in balloons?
A. Oxygen
B. Nitrogen
C. Helium ✅
D. Carbon dioxide
Explanation:
Helium is a light, non-flammable gas, safer than hydrogen. It is used in balloons and airships.
75. The SI unit of frequency is:
A. Joule
B. Newton
C. Hertz ✅
D. Watt
Explanation:
Frequency is measured in Hertz (Hz), meaning cycles per second. For example, AC electricity in Pakistan runs at 50 Hz.
76. Which vitamin helps in blood clotting?
A. Vitamin A
B. Vitamin B
C. Vitamin K ✅
D. Vitamin D
Explanation:
Vitamin K helps in the synthesis of clotting factors. Deficiency can cause excessive bleeding.
77. The most abundant metal in the Earth’s crust is:
A. Iron
B. Copper
C. Calcium
D. Aluminium ✅
Explanation:
Aluminium is the most abundant metal in Earth’s crust, though iron is more abundant overall inside the planet.
78. What is the chemical symbol of gold?
A. Go
B. Gd
C. Ag
D. Au ✅
Explanation:
The symbol Au comes from the Latin word “Aurum”, meaning shining dawn.
79. Which organ is affected by hepatitis?
A. Kidney
B. Heart
C. Lungs
D. Liver ✅
Explanation:
Hepatitis is inflammation of the liver, usually caused by viruses (Hepatitis A, B, C), toxins, or alcohol.
80. Which scientist proposed the three laws of motion?
A. Albert Einstein
B. Galileo Galilei
C. Isaac Newton ✅
D. Johannes Kepler
Explanation:
Sir Isaac Newton proposed the laws of motion, which form the foundation of classical mechanics.
81. The hardest natural substance on Earth is:
A. Iron
B. Quartz
C. Steel
D. Diamond ✅
Explanation:
Diamond is the hardest naturally occurring material, with a Mohs hardness of 10. It is used in cutting tools and jewelry.
82. Which part of the cell contains genetic material?
A. Cytoplasm
B. Mitochondria
C. Nucleus ✅
D. Ribosome
Explanation:
The nucleus stores DNA, which controls cell activities and passes genetic information to new cells.
83. The instrument used to measure atmospheric pressure is:
A. Thermometer
B. Barometer ✅
C. Hygrometer
D. Altimeter
Explanation:
A barometer measures air pressure, useful in predicting weather changes.
84. Which vitamin is also called ascorbic acid?
A. Vitamin A
B. Vitamin D
C. Vitamin K
D. Vitamin C ✅
Explanation:
Vitamin C (ascorbic acid) helps in wound healing, immunity, and preventing scurvy.
85. Which planet has the largest number of moons?
A. Earth
B. Mars
C. Saturn
D. Jupiter ✅
Explanation:
As of recent data, Jupiter has 95 moons, making it the planet with the largest number of known satellites.
86. Which is the largest gland in the human body?
A. Kidney
B. Pancreas
C. Thyroid
D. Liver ✅
Explanation:
The liver is the largest gland, playing roles in digestion, metabolism, detoxification, and storage of nutrients.
87. Sound travels fastest in:
A. Air
B. Water
C. Vacuum
D. Steel ✅
Explanation:
Sound travels fastest in solids because molecules are tightly packed. It moves faster in steel than in water or air.
88. The gas responsible for global warming is:
A. Oxygen
B. Nitrogen
C. Carbon dioxide ✅
D. Argon
Explanation:
Carbon dioxide (CO₂) traps heat in the atmosphere, causing the greenhouse effect and climate change.
89. The smallest unit of matter is:
A. Molecule
B. Atom ✅
C. Proton
D. Electron
Explanation:
An atom is the smallest unit of matter that retains chemical properties. Molecules are made of two or more atoms.
90. Who discovered gravity?
A. Galileo Galilei
B. Isaac Newton ✅
C. James Watt
D. Michael Faraday
Explanation:
Isaac Newton formulated the law of universal gravitation after observing an apple fall, explaining attraction between masses.
91. The most abundant gas in the Earth’s atmosphere is:
A. Oxygen
B. Carbon dioxide
C. Nitrogen ✅
D. Argon
Explanation:
About 78% of Earth’s atmosphere is nitrogen, followed by oxygen (21%) and other gases in trace amounts.
92. Which metal is liquid at room temperature?
A. Sodium
B. Potassium
C. Mercury ✅
D. Calcium
Explanation:
Mercury is the only metal that remains liquid at room temperature. It is used in thermometers and barometers.
93. Which planet is called the “Morning Star” or “Evening Star”?
A. Mars
B. Venus ✅
C. Mercury
D. Saturn
Explanation:
Venus is the brightest planet visible from Earth and is often seen near sunrise or sunset, hence called the “Morning Star” or “Evening Star.”
94. The process by which plants lose water through small pores in leaves is called:
A. Photosynthesis
B. Transpiration ✅
C. Respiration
D. Evaporation
Explanation:
Transpiration occurs through stomata in leaves, helping in nutrient transport and temperature regulation.
95. Which vitamin helps in blood clotting?
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K ✅
Explanation:
Vitamin K is essential for the synthesis of clotting factors that prevent excessive bleeding.
96. Which organ purifies blood in the human body?
A. Heart
B. Kidney ✅
C. Liver
D. Lungs
Explanation:
The kidneys filter waste products from blood and maintain water-salt balance, producing urine.
97. The study of earthquakes is called:
A. Geology
B. Seismology ✅
C. Meteorology
D. Oceanography
Explanation:
Seismology is the study of earthquakes and seismic waves, using instruments like seismographs.
98. Which is the lightest element?
A. Oxygen
B. Carbon
C. Helium
D. Hydrogen ✅
Explanation:
Hydrogen is the lightest element with an atomic number of 1 and is the most abundant element in the universe.
99. The ozone layer is mainly found in which layer of the atmosphere?
A. Troposphere
B. Stratosphere ✅
C. Mesosphere
D. Thermosphere
Explanation:
The ozone layer in the stratosphere absorbs harmful ultraviolet (UV) radiation from the sun, protecting life on Earth.
100. Which gas is used in balloons to make them float?
A. Oxygen
B. Carbon dioxide
C. Helium ✅
D. Nitrogen
Explanation:
Helium is lighter than air, non-flammable, and safe to use in balloons, unlike hydrogen which is explosive.
This was Set 2 (MCQs) of Everyday Science with explanations. Continue your journey with the next sets to cover the complete series.
👉 Explore more:
- Everyday Science MCQs – Set 1
- Everyday Science MCQs – Set 3
- General Knowledge MCQs for Competitive Exams
With consistent practice, you will not only master Everyday Science but also boost your confidence in solving tricky questions under exam conditions. 🚀