Introduction
Everyday Science is one of the most important subjects for CSS, PMS, PPSC, SPSC, FPSC, UPSC, and one-paper competitive exams. Students often struggle with scientific facts, formulas, and concepts because most books provide only direct questions and answers without explanations.
To help you master this subject, we have prepared 100 highly valuable Everyday Science MCQs with answers and explanations. Each question is designed to not only help you in exams but also to clear your concepts for long-term retention.
Whether you are preparing for CSS, PMS, FPSC, UPSC, NTS, PPSC, SPSC, KPPSC, BPSC, or general science quizzes, this collection will give you an edge in your preparation.
1.
The common salt present in sweat is:
A) Calcium Oxalate
B) Potassium Sulphate
C) Sodium Chloride ✅
D) Iron Sulphate
Explanation: Sweat is mainly composed of water and sodium chloride (NaCl). Salt in sweat helps regulate body temperature during evaporation.
2.
Which part of the eye is sensitive to light?
A) Choroid
B) Retina ✅
C) Sclerotic
D) Cornea
Explanation: The retina contains rods and cones that detect light and send signals to the brain through the optic nerve.
3.
Laughing gas is chemically known as:
A) Carbon Monoxide
B) Nitrous Oxide ✅
C) Nitric Oxide
D) Ammonia
Explanation: N₂O (Nitrous Oxide) is commonly called laughing gas. It is used as an anesthetic in dentistry and minor surgeries.
4.
Dr. Abdus Salam of Pakistan won the Nobel Prize for his contribution to:
A) Quantum Physics
B) Electroweak Theory ✅
C) Atomic Bomb Research
D) Space Science
Explanation: Dr. Abdus Salam was awarded the 1979 Nobel Prize in Physics for the unification of electromagnetic and weak nuclear forces.
5.
Which triplet (codon) in DNA codes for valine?
A) CTT
B) CAT ✅
C) AGU
D) AAT
Explanation: Codons GTT, GTC, GTA, GTG in DNA code for valine. Among the options, CAT corresponds to valine in transcription.
6.
The gas used in fire extinguishers is:
A) Oxygen
B) Carbon Dioxide ✅
C) Nitrogen
D) Hydrogen
Explanation: CO₂ is used because it displaces oxygen and smothers fire without leaving residue.
7.
Which vitamin is produced in the skin by sunlight?
A) Vitamin A
B) Vitamin B12
C) Vitamin C
D) Vitamin D ✅
Explanation: Sunlight helps the skin produce Vitamin D, which is essential for calcium absorption and bone health.
8.
Which instrument measures atmospheric pressure?
A) Thermometer
B) Barometer ✅
C) Hygrometer
D) Altimeter
Explanation: A barometer measures atmospheric pressure. Mercury barometers are most common.
9.
The fastest rotating planet in the Solar System is:
A) Earth
B) Saturn
C) Jupiter ✅
D) Mars
Explanation: Jupiter completes one rotation in just 10 hours, making it the fastest-rotating planet.
10.
Which blood group is called the universal donor?
A) A
B) AB
C) O negative ✅
D) B
Explanation: People with O-negative blood can donate to anyone, making them universal donors.
11.
The unit of electric current is:
A) Volt
B) Watt
C) Ohm
D) Ampere ✅
Explanation: Ampere (A) is the SI unit of electric current, named after André-Marie Ampère.
12.
Which is the hardest natural substance on Earth?
A) Gold
B) Iron
C) Diamond ✅
D) Quartz
Explanation: Diamond, a form of carbon, is the hardest naturally occurring substance.
13.
Which part of the plant makes food?
A) Root
B) Stem
C) Leaf ✅
D) Flower
Explanation: Leaves perform photosynthesis, producing food for the plant using sunlight, CO₂, and water.
14.
Which gas is most abundant in Earth’s atmosphere?
A) Oxygen
B) Nitrogen ✅
C) Carbon Dioxide
D) Argon
Explanation: The atmosphere is 78% Nitrogen, 21% Oxygen, and small amounts of other gases.
15.
The red color of blood is due to the presence of:
A) Hemocyanin
B) Hemoglobin ✅
C) Myoglobin
D) Chlorophyll
Explanation: Hemoglobin, which contains iron, gives blood its red color and helps transport oxygen.
16.
Which part of the human brain controls balance and posture?
A) Cerebrum
B) Cerebellum ✅
C) Medulla Oblongata
D) Hypothalamus
Explanation: The cerebellum is responsible for balance, posture, and coordination of movements.
17.
Which planet is known as the “Red Planet”?
A) Venus
B) Mars ✅
C) Mercury
D) Jupiter
Explanation: Mars appears red due to iron oxide (rust) on its surface.
18.
The speed of light in vacuum is approximately:
A) 2 × 10⁶ m/s
B) 3 × 10⁸ m/s ✅
C) 1.5 × 10⁸ m/s
D) 2.5 × 10⁷ m/s
Explanation: The universal constant for the speed of light in a vacuum is 299,792,458 m/s (~3 × 10⁸ m/s).
19.
Which gas is used in balloons to make them float?
A) Hydrogen
B) Helium ✅
C) Oxygen
D) Methane
Explanation: Helium is used because it is lighter than air and non-flammable, unlike hydrogen.
20.
Which is the smallest unit of heredity?
A) Gene ✅
B) Chromosome
C) DNA
D) Ribosome
Explanation: A gene is the basic unit of heredity, carrying instructions for making proteins.
21.
The study of earthquakes is called:
A) Seismology ✅
B) Geology
C) Volcanology
D) Geography
Explanation: Seismology deals with the study of earthquakes and seismic waves.
22.
What is the chemical formula of ozone?
A) O₂
B) O₃ ✅
C) CO₂
D) NO₂
Explanation: Ozone is a triatomic form of oxygen (O₃), found in the stratosphere, protecting Earth from harmful UV rays.
23.
Which vitamin prevents scurvy?
A) Vitamin A
B) Vitamin C ✅
C) Vitamin D
D) Vitamin K
Explanation: Lack of Vitamin C causes scurvy, leading to bleeding gums and weakness.
24.
Which blood cells help in clotting?
A) Red blood cells
B) White blood cells
C) Platelets ✅
D) Plasma
Explanation: Platelets (thrombocytes) are responsible for blood clotting by forming fibrin clots.
25.
Which is the lightest metal?
A) Sodium
B) Lithium ✅
C) Magnesium
D) Potassium
Explanation: Lithium is the lightest known metal, with atomic number 3.
26.
Which of the following is a greenhouse gas?
A) Carbon Dioxide ✅
B) Oxygen
C) Argon
D) Nitrogen
Explanation: CO₂ is the primary greenhouse gas causing global warming. Others include methane, nitrous oxide, and CFCs.
27.
What is the chemical name of baking soda?
A) Sodium Hydroxide
B) Sodium Chloride
C) Sodium Bicarbonate ✅
D) Sodium Carbonate
Explanation: NaHCO₃ (Sodium Bicarbonate) is commonly called baking soda.
28.
Which organ in the human body produces insulin?
A) Liver
B) Pancreas ✅
C) Kidney
D) Stomach
Explanation: The pancreas produces insulin, which regulates blood sugar levels.
29.
Which device converts sound energy into electrical signals?
A) Speaker
B) Microphone ✅
C) Amplifier
D) Telephone
Explanation: A microphone converts sound waves into electrical signals, used in communication systems.
30.
Which layer of the Earth is liquid?
A) Crust
B) Mantle
C) Outer Core ✅
D) Inner Core
Explanation: The outer core is liquid, mainly composed of iron and nickel, and responsible for Earth’s magnetic field.
31.
Which blood group is called the “universal donor”?
A) A+
B) B–
C) O– ✅
D) AB+
Explanation: O– blood can be donated to all blood groups because it lacks A, B, and Rh antigens.
32.
Which planet has the largest number of moons?
A) Earth
B) Saturn ✅
C) Jupiter
D) Neptune
Explanation: As of 2023, Saturn has 83 confirmed moons, the most in the solar system.
33.
Which gas do plants absorb during photosynthesis?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide ✅
D) Hydrogen
Explanation: Plants absorb CO₂ and release oxygen while producing glucose during photosynthesis.
34.
Which scientist proposed the theory of relativity?
A) Isaac Newton
B) Albert Einstein ✅
C) Galileo Galilei
D) Niels Bohr
Explanation: Einstein’s theory of relativity (1905, 1915) revolutionized physics by linking space, time, and gravity.
35.
Which organ in the human body is responsible for detoxification?
A) Heart
B) Liver ✅
C) Kidney
D) Lungs
Explanation: The liver detoxifies harmful substances and produces bile for digestion.
36.
What is the SI unit of force?
A) Joule
B) Watt
C) Newton ✅
D) Pascal
Explanation: The Newton (N) is the SI unit of force, equal to 1 kg·m/s².
37.
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 atmospheric pressure, water boils at 100°C.
38.
Which layer of the atmosphere contains the ozone layer?
A) Troposphere
B) Stratosphere ✅
C) Mesosphere
D) Thermosphere
Explanation: The ozone layer lies in the stratosphere, protecting Earth from harmful UV radiation.
39.
Which vitamin is also known as calciferol?
A) Vitamin B12
B) Vitamin D ✅
C) Vitamin K
D) Vitamin E
Explanation: Vitamin D (Calciferol) is essential for bone health and calcium absorption.
40.
Which metal is used in galvanization?
A) Zinc ✅
B) Copper
C) Iron
D) Aluminium
Explanation: Galvanization is the coating of iron/steel with zinc to prevent rusting.
41.
Which gland is known as the “master gland”?
A) Thyroid
B) Pituitary ✅
C) Adrenal
D) Pancreas
Explanation: The pituitary gland controls the activity of other endocrine glands.
42.
Which planet is closest to the Sun?
A) Venus
B) Mercury ✅
C) Mars
D) Jupiter
Explanation: Mercury is the closest planet to the Sun, with an orbital period of 88 days.
43.
Which gas is essential for respiration in humans?
A) Oxygen ✅
B) Carbon Dioxide
C) Nitrogen
D) Helium
Explanation: Oxygen is vital for cellular respiration, producing energy in the form of ATP.
44.
Which element has the chemical symbol ‘K’?
A) Calcium
B) Potassium ✅
C) Krypton
D) Phosphorus
Explanation: K stands for Potassium (from Latin Kalium).
45.
Which device measures atmospheric pressure?
A) Thermometer
B) Barometer ✅
C) Hygrometer
D) Anemometer
Explanation: A barometer measures air pressure and is used in weather forecasting.
46.
Which part of the human eye controls the amount of light entering?
A) Retina
B) Cornea
C) Iris ✅
D) Lens
Explanation: The iris controls the size of the pupil, regulating how much light enters the eye.
47.
Which scientist is called the “Father of Modern Chemistry”?
A) Robert Boyle
B) Antoine Lavoisier ✅
C) Dmitri Mendeleev
D) John Dalton
Explanation: Lavoisier discovered the role of oxygen in combustion and helped develop the modern chemical nomenclature.
48.
Which blood group is called the “universal recipient”?
A) O+
B) AB+ ✅
C) A+
D) B–
Explanation: AB+ can receive blood from all groups due to the presence of all major antigens.
49.
Which type of energy is produced in nuclear reactions?
A) Solar Energy
B) Nuclear Energy ✅
C) Thermal Energy
D) Mechanical Energy
Explanation: Nuclear fission and fusion release nuclear energy, used in power plants and weapons.
50.
Which is the hardest natural substance on Earth?
A) Iron
B) Diamond ✅
C) Quartz
D) Platinum
Explanation: Diamond, made of carbon, is the hardest natural material with the highest Mohs hardness rating of 10.
51.
Which is the largest internal organ in the human body?
A) Kidney
B) Heart
C) Liver ✅
D) Lung
Explanation: The liver is the largest internal organ, playing roles in digestion, detoxification, and metabolism.
52.
Which is the lightest gas?
A) Helium
B) Hydrogen ✅
C) Neon
D) Oxygen
Explanation: Hydrogen is the lightest gas and the first element in the periodic table.
53.
Which vitamin prevents rickets?
A) Vitamin C
B) Vitamin D ✅
C) Vitamin B12
D) Vitamin A
Explanation: Vitamin D helps calcium absorption and prevents rickets, a bone-softening disease.
54.
Which instrument is used to measure humidity?
A) Thermometer
B) Hygrometer ✅
C) Barometer
D) Altimeter
Explanation: A hygrometer measures the amount of water vapor (humidity) in the air.
55.
Which organ purifies blood in the human body?
A) Lungs
B) Kidneys ✅
C) Stomach
D) Pancreas
Explanation: Kidneys filter waste products from blood and maintain fluid balance.
56.
Which gas is commonly known as “laughing gas”?
A) Oxygen
B) Nitrogen
C) Nitrous Oxide (N₂O) ✅
D) Carbon Dioxide
Explanation: Nitrous Oxide is called laughing gas because of its anesthetic and euphoric effects.
57.
Which vitamin helps in blood clotting?
A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin K ✅
Explanation: Vitamin K is essential for producing proteins that help in blood clotting.
58.
Which is the fastest land animal?
A) Horse
B) Cheetah ✅
C) Lion
D) Tiger
Explanation: The cheetah can run up to 110 km/h, making it the fastest land animal.
59.
Which acid is present in vinegar?
A) Acetic Acid ✅
B) Citric Acid
C) Lactic Acid
D) Hydrochloric Acid
Explanation: Vinegar contains acetic acid, giving it a sour taste.
60.
Which is the nearest star to Earth after the Sun?
A) Proxima Centauri ✅
B) Sirius
C) Alpha Centauri
D) Betelgeuse
Explanation: Proxima Centauri, about 4.24 light years away, is the nearest star to Earth.
61.
What is the SI unit of pressure?
A) Newton
B) Pascal ✅
C) Watt
D) Joule
Explanation: The Pascal (Pa) is the SI unit of pressure, equal to 1 N/m².
62.
Which gas is used in refrigerators and air conditioners?
A) Methane
B) Chlorofluorocarbons (CFCs) ✅
C) Ammonia
D) Oxygen
Explanation: CFCs and other refrigerants are used in cooling systems but harm the ozone layer.
63.
Which part of the plant carries out photosynthesis?
A) Root
B) Stem
C) Leaf ✅
D) Flower
Explanation: Leaves contain chlorophyll, which absorbs sunlight for photosynthesis.
64.
Which blood cells fight against infections?
A) Red Blood Cells
B) White Blood Cells ✅
C) Platelets
D) Plasma
Explanation: WBCs protect the body by fighting bacteria, viruses, and infections.
65.
Which gas is produced during respiration?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide ✅
D) Hydrogen
Explanation: Human respiration releases CO₂ as a waste product.
66.
Which instrument is used to measure earthquakes?
A) Seismograph ✅
B) Barometer
C) Hygrometer
D) Telescope
Explanation: A seismograph records the strength and duration of earthquakes.
67.
Which metal is liquid at room temperature?
A) Iron
B) Mercury ✅
C) Sodium
D) Lead
Explanation: Mercury is the only liquid metal at room temperature.
68.
Which is the smallest planet in our solar system?
A) Mercury ✅
B) Mars
C) Venus
D) Pluto
Explanation: Mercury is the smallest planet since Pluto is now classified as a dwarf planet.
69.
Which vitamin is also called ascorbic acid?
A) Vitamin B12
B) Vitamin C ✅
C) Vitamin D
D) Vitamin K
Explanation: Vitamin C (Ascorbic acid) boosts immunity and prevents scurvy.
70.
Which scientist discovered gravity?
A) Galileo
B) Kepler
C) Isaac Newton ✅
D) Einstein
Explanation: Newton discovered the law of gravity in the 17th century.
71.
Which gas is most abundant in Earth’s atmosphere?
A) Oxygen
B) Nitrogen ✅
C) Carbon Dioxide
D) Argon
Explanation: Nitrogen makes up about 78% of Earth’s atmosphere.
72.
Which device is used to measure electric current?
A) Ammeter ✅
B) Voltmeter
C) Ohmmeter
D) Galvanometer
Explanation: An ammeter measures electric current in a circuit.
73.
Which part of the plant absorbs water and minerals?
A) Leaf
B) Stem
C) Root ✅
D) Flower
Explanation: Roots absorb water and minerals from the soil.
74.
Which is the chemical name of table salt?
A) Sodium Sulfate
B) Sodium Chloride (NaCl) ✅
C) Sodium Carbonate
D) Potassium Chloride
Explanation: Table salt is NaCl, essential for human health and food preservation.
75.
Which device is used to measure wind speed?
A) Hygrometer
B) Barometer
C) Anemometer ✅
D) Thermometer
Explanation: An anemometer measures wind speed and direction.
76.
Which planet is called the “Red Planet”?
A) Venus
B) Mars ✅
C) Jupiter
D) Saturn
Explanation: Mars is called the Red Planet due to its iron oxide-rich surface, giving it a reddish appearance.
77.
Which blood group is known as the universal donor?
A) A
B) B
C) AB
D) O Negative ✅
Explanation: O Negative can be donated to all blood groups, making it the universal donor.
78.
Which element is essential for strong bones and teeth?
A) Iron
B) Calcium ✅
C) Potassium
D) Magnesium
Explanation: Calcium strengthens bones and teeth and prevents osteoporosis.
79.
Which organ of the human body produces insulin?
A) Liver
B) Pancreas ✅
C) Kidney
D) Stomach
Explanation: The pancreas produces insulin, which regulates blood sugar levels.
80.
Which part of the eye controls the amount of light entering it?
A) Retina
B) Cornea
C) Iris ✅
D) Lens
Explanation: The iris adjusts pupil size, controlling light entry.
81.
Which element is needed for hemoglobin formation?
A) Zinc
B) Iron ✅
C) Calcium
D) Magnesium
Explanation: Iron is essential for hemoglobin, which carries oxygen in the blood.
82.
Which is the main source of Vitamin D?
A) Sunlight ✅
B) Fish
C) Milk
D) Eggs
Explanation: The human body synthesizes Vitamin D when exposed to sunlight.
83.
Which is the largest gland in the human body?
A) Kidney
B) Pancreas
C) Liver ✅
D) Thyroid
Explanation: The liver is the largest gland, aiding digestion and detoxification.
84.
Which gas is commonly used in balloons?
A) Oxygen
B) Hydrogen
C) Helium ✅
D) Nitrogen
Explanation: Helium is non-flammable and lighter than air, making it safe for balloons.
85.
Which is the hardest natural substance?
A) Iron
B) Diamond ✅
C) Quartz
D) Steel
Explanation: Diamond is the hardest naturally occurring substance.
86.
Which vitamin is essential for good eyesight?
A) Vitamin A ✅
B) Vitamin B12
C) Vitamin D
D) Vitamin E
Explanation: Vitamin A prevents night blindness and supports vision health.
87.
Which gas is absorbed by plants during photosynthesis?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide ✅
D) Hydrogen
Explanation: Plants absorb CO₂ and release oxygen during photosynthesis.
88.
Which instrument is used to measure atmospheric pressure?
A) Hygrometer
B) Barometer ✅
C) Thermometer
D) Seismograph
Explanation: A barometer measures atmospheric pressure, useful for weather forecasting.
89.
Which blood group is known as the universal recipient?
A) O Positive
B) AB Positive ✅
C) B Negative
D) A Positive
Explanation: AB Positive can receive blood from all groups, making it the universal recipient.
90.
Which gas is responsible for the greenhouse effect?
A) Oxygen
B) Nitrogen
C) Carbon Dioxide ✅
D) Helium
Explanation: Carbon Dioxide traps heat in the atmosphere, causing global warming.
91.
Which is the most abundant element in the Earth’s crust?
A) Silicon
B) Oxygen ✅
C) Aluminum
D) Iron
Explanation: Oxygen makes up nearly 47% of the Earth’s crust by weight.
92.
Which organ of the human body stores bile?
A) Stomach
B) Pancreas
C) Gallbladder ✅
D) Kidney
Explanation: The gallbladder stores bile, which helps digest fats.
93.
Which gas is necessary for respiration?
A) Nitrogen
B) Carbon Dioxide
C) Oxygen ✅
D) Hydrogen
Explanation: Oxygen is vital for respiration and energy production in cells.
94.
Which part of the cell contains genetic material?
A) Cytoplasm
B) Nucleus ✅
C) Ribosome
D) Mitochondria
Explanation: The nucleus contains DNA, the genetic material of the cell.
95.
Which is the largest planet in the solar system?
A) Earth
B) Saturn
C) Jupiter ✅
D) Neptune
Explanation: Jupiter is the largest planet with a strong magnetic field and 80+ moons.
96.
Which scientist discovered the circulation of blood?
A) Pasteur
B) William Harvey ✅
C) Darwin
D) Newton
Explanation: William Harvey discovered blood circulation in 1628.
97.
Which organ is called the “control center” of the human body?
A) Heart
B) Brain ✅
C) Liver
D) Kidney
Explanation: The brain controls body functions, memory, and decision-making.
98.
Which is the main gas in the Sun?
A) Helium
B) Hydrogen ✅
C) Oxygen
D) Carbon
Explanation: The Sun is mainly composed of hydrogen (about 74%) and helium.
99.
Which organ of the body is affected by pneumonia?
A) Heart
B) Kidney
C) Lungs ✅
D) Liver
Explanation: Pneumonia is an infection that inflames the lungs.
100.
Which scientist proposed the theory of relativity?
A) Newton
B) Galileo
C) Einstein ✅
D) Planck
Explanation: Albert Einstein proposed the theory of relativity, revolutionizing physics.
This was Set 1 (MCQs 1–100) of Everyday Science with explanations. In the next sets, we will cover more advanced and tricky questions (MCQs 101–500) to make sure you are fully prepared for your exams.
👉 Explore more:
- https://tayarimcqs.com/everyday-science-mcqs-set-2/Everyday Science MCQs – Set 2
- General Knowledge MCQs Collection
- Islamiyat MCQs Collection
Keep practicing daily, and soon Everyday Science will become your strongest subject. 🚀