20 Most Repeated Everyday Science MCQs for NTS, CSS, PMS, KPPSC, PPSC, ETEA, SPSC, BPSC, and FPSC Tests

Here is most repeated Everyday Science MCQs. These questions frequently appear in past papers for NTS, CSS, PMS, and various provincial public service commission exams, making them essential for your test preparation.

Most Repeated Everyday Science MCQs

1. What is the average lifespan of a Red Blood Cell (RBC) in the human body?

A) 60 days
B) 90 days
C) 120 days
D) 150 days
Correct Answer: C) 120 days

Explanation: Red blood cells (erythrocytes) circulate in the blood for about 120 days before they become damaged or worn out and are removed by the spleen and liver.

2. What is the chemical name for "Heavy Water"?

A) Hydrogen Peroxide
B) Deuterium Oxide
C) Tritium Oxide
D) Calcium Oxide
Correct Answer: B) Deuterium Oxide

Explanation: Heavy water is composed of oxygen and deuterium, which is a heavier isotope of hydrogen. It is often used as a moderator in nuclear reactors.

3. Which instrument is used to measure atmospheric pressure?

A) Hygrometer
B) Lactometer
C) Barometer
D) Galvanometer
Correct Answer: C) Barometer

Explanation: A barometer measures atmospheric pressure, which is crucial for forecasting weather. A hygrometer measures humidity, and a lactometer measures the purity of milk.

4. What is the most abundant element in the universe?

A) Oxygen
B) Hydrogen
C) Carbon
D) Helium
Correct Answer: B) Hydrogen

Explanation: Hydrogen makes up about 75% of the normal matter in the universe, serving as the primary fuel for stars, including our Sun.

5. "Dry Ice" is the solid form of which gas?

A) Nitrogen
B) Oxygen
C) Carbon Monoxide
D) Carbon Dioxide
Correct Answer: D) Carbon Dioxide

Explanation: Dry ice is solid carbon dioxide. It is called "dry" because it sublimates (turns directly from a solid into a gas) without leaving any liquid residue.

6. What is the normal temperature of the human body?

A) 35°C
B) 37°C
C) 39°C
D) 41°C
Correct Answer: B) 37°C

Explanation: The normal core body temperature for a healthy human is generally accepted to be around 37°C (which is equivalent to 98.6°F).

7. In the human body, the digestion of food is entirely completed in the:

A) Stomach
B) Large Intestine
C) Small Intestine
D) Liver
Correct Answer: C) Small Intestine

Explanation: While digestion begins in the mouth and continues in the stomach, the final breakdown of food and the absorption of nutrients occur almost entirely in the small intestine.

8. Which of the following are the primary colors of light?

A) Red, Yellow, Blue
B) Red, Green, Blue
C) Cyan, Magenta, Yellow
D) Orange, Green, Purple
Correct Answer: B) Red, Green, Blue

Explanation: In physics and electronics (like TV screens and monitors), the primary colors of light are Red, Green, and Blue (RGB). Mixing these colors of light in various proportions can create any other color.

9. A person with which blood group is known as a "Universal Recipient"?

A) O negative
B) A positive
C) AB positive
D) B negative
Correct Answer: C) AB positive

Explanation: People with AB positive blood have both A and B antigens on their red blood cells, as well as the Rh factor, meaning their immune system will not attack transfused blood of any type.

10. Which vitamin is primarily synthesized in the human skin through exposure to sunlight?

A) Vitamin A
B) Vitamin B12
C) Vitamin C
D) Vitamin D
Correct Answer: D) Vitamin D

Explanation: When ultraviolet B (UVB) rays from the sun hit the skin, they trigger a chemical reaction that produces Vitamin D, which is essential for bone health.

11. What is the hardest naturally occurring substance on Earth?

A) Gold
B) Iron
C) Diamond
D) Platinum
Correct Answer: C) Diamond

Explanation: Diamond is a solid form of pure carbon with its atoms arranged in a highly rigid crystal structure, making it the hardest known natural material.

12. Bile is a digestive fluid produced by the:

A) Pancreas
B) Gallbladder
C) Liver
D) Stomach
Correct Answer: C) Liver

Explanation: The liver produces bile, which helps break down and absorb fats. The gallbladder merely stores and concentrates the bile until it is needed.

13. Which gas is the primary contributor to the greenhouse effect and global warming?

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Argon
Correct Answer: C) Carbon Dioxide

Explanation: While other gases like methane are also potent greenhouse gases, Carbon Dioxide is the primary contributor due to the sheer volume emitted by human activities, such as burning fossil fuels.

14. Which is the lightest of all known gases?

A) Helium
B) Hydrogen
C) Nitrogen
D) Neon
Correct Answer: B) Hydrogen

Explanation: Hydrogen is the first element on the periodic table and has the lowest atomic weight, making it the lightest gas. Helium is the second lightest.

15. Sound waves cannot travel through:

A) Solids
B) Liquids
C) Gases
D) A Vacuum
Correct Answer: D) A Vacuum

Explanation: Sound relies on the vibration of particles in a medium (like air, water, or steel) to propagate. Because a vacuum is entirely empty of matter, sound cannot travel through it.

16. What is the SI unit of Force?

A) Joule
B) Pascal
C) Newton
D) Watt
Correct Answer: C) Newton

Explanation: Force is measured in Newtons (N). One Newton is the force needed to accelerate one kilogram of mass at the rate of one meter per second squared.

17. Which planet is closest to the Sun?

A) Venus
B) Mars
C) Mercury
D) Earth
Correct Answer: C) Mercury

Explanation: Mercury is the innermost planet in our solar system. Despite being closest to the Sun, Venus is actually hotter due to its thick atmosphere.

18. Which instrument is used to measure electrical current in a circuit?

A) Voltmeter
B) Ammeter
C) Multimeter
D) Ohmmeter
Correct Answer: B) Ammeter

Explanation: An ammeter is used to measure the current flowing through a circuit in amperes (amps). A voltmeter measures voltage, and an ohmmeter measures resistance.

19. A deficiency of Vitamin A primarily causes:

A) Scurvy
B) Rickets
C) Night Blindness
D) Anemia
Correct Answer: C) Night Blindness

Explanation: Vitamin A is crucial for maintaining a clear cornea and is a component of rhodopsin, a protein in your eyes that allows you to see in low light conditions.

20. What is the approximate speed of light in a vacuum?

A) 300,000 km/s
B) 150,000 km/s
C) 1,000,000 km/s
D) 50,000 km/s
Correct Answer: A) 300,000 km/s

Explanation: Light travels at a constant, finite speed of 299,792 kilometers per second in a vacuum, which is generally rounded to 300,000 km/s for simplicity in everyday science.