Question 1

Which disease is caused by the deficiency of Vitamin C?

Accepted Answer

Correct Answer: Scurvy

Explanation: Scurvy is caused by a severe deficiency of Vitamin C (ascorbic acid). Symptoms include bleeding gums, loose teeth, weakness, and bruising. Historically, sailors on long voyages often suffered from scurvy due to a lack of fresh fruits and vegetables. It is easily treated and prevented by consuming citrus fruits like oranges and lemons.

Question 2

What is the cause of the blue color of the sky?

Accepted Answer

Correct Answer: Scattering of Light

Explanation: The sky appears blue due to Rayleigh Scattering. As sunlight reaches Earth's atmosphere, it collides with gas molecules (nitrogen and oxygen). Shorter wavelengths (blue and violet) are scattered more strongly than longer wavelengths (red). Although violet is scattered more, our eyes are more sensitive to blue, so we see the sky as blue.

Question 3

Which gland is known as the 'Master Gland' of the human body?

Accepted Answer

Correct Answer: Pituitary

Explanation: The Pituitary Gland is called the Master Gland because it produces hormones that control many other endocrine glands in the body, such as the thyroid and adrenal glands. It is a pea-sized gland located at the base of the brain. It regulates growth, blood pressure, reproduction, and many other vital bodily functions.

Question 4

The chemical symbol for Silver is:

Accepted Answer

Correct Answer: Ag

Explanation: The chemical symbol for Silver is 'Ag', derived from the Latin word 'Argentum'. Silver is a white, lustrous transition metal known for having the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. It is used in jewelry, solar panels, electronics, and mirrors.

Question 5

Which planet rotates on its axis from East to West?

Accepted Answer

Correct Answer: Venus

Explanation: Venus is unique because it rotates on its axis from East to West, a direction opposite to most other planets (retrograde rotation). This means that on Venus, the Sun rises in the west and sets in the east. Its rotation is also very slow; a day on Venus is longer than a year on Venus.

Question 6

What is the main constituent of Hemoglobin?

Accepted Answer

Correct Answer: Iron

Explanation: Iron is the central component of Hemoglobin, the protein in red blood cells that carries oxygen. The iron ion forms the center of the heme group, which binds to oxygen molecules in the lungs and releases them in the tissues. Without sufficient iron, the body cannot produce enough healthy hemoglobin, leading to anemia.

Question 7

Which gas acts as a shield against UV radiation?

Accepted Answer

Correct Answer: Ozone

Explanation: Ozone (O3) is a gas present in the Earth's stratosphere that forms the Ozone Layer. It absorbs the majority of the Sun's harmful ultraviolet (UV-B) radiation. Without this protective layer, life on Earth would be exposed to dangerous levels of radiation, leading to increased skin cancer, cataracts, and damage to ecosystems.

Question 8

The purity of Gold is measured in:

Accepted Answer

Correct Answer: Carats

Explanation: The purity of gold is measured in Carats (K). 24-carat gold is considered 99.9% pure gold, but it is very soft and not suitable for most jewelry. Therefore, it is often mixed with metals like copper or silver to increase hardness. For example, 18-carat gold contains 75% gold and 25% other metals.

Question 9

What is the phenomenon behind the formation of a Rainbow?

Accepted Answer

Correct Answer: Refraction and Dispersion

Explanation: A rainbow is caused by the Refraction, Dispersion, and Reflection of light in water droplets. When sunlight enters a raindrop, it slows down and bends (refracts), then splits into its component colors (dispersion), reflects off the back of the drop, and refracts again as it leaves. This separates white light into the spectrum of colors we see.

Question 10

Which acid is found in Lemons?

Accepted Answer

Correct Answer: Citric Acid

Explanation: Lemons and other citrus fruits contain Citric Acid. It is a weak organic acid that gives lemons their characteristic sour taste. It acts as a natural preservative and is also used to add an acidic or sour taste to foods and soft drinks. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.

Question 11

Which is the longest bone in the human body?

Accepted Answer

Correct Answer: Femur

Explanation: The Femur, or thigh bone, is the longest, heaviest, and strongest bone in the human body. It extends from the hip to the knee. It supports the weight of the body and allows for the forces of the legs to be transmitted to the rest of the body. On average, it makes up about a quarter of a person's height.

Question 12

Myopia is a defect of which organ?

Accepted Answer

Correct Answer: Eyes

Explanation: Myopia, or nearsightedness, is a vision condition where close objects appear clear, but far ones look blurry. It happens when the shape of the eye causes light rays to bend (refract) incorrectly, focusing images in front of the retina instead of on it. It is usually corrected with concave lenses (glasses or contacts) or laser surgery.

Question 13

Which instrument is used to measure Earthquake intensity?

Accepted Answer

Correct Answer: Richter Scale

Explanation: The Richter Scale is a logarithmic scale used to express the magnitude or energy released by an earthquake. Developed by Charles Richter in 1935, it assigns a number to quantify the size of an earthquake. A quake of magnitude 2.0 is rarely felt, while a magnitude 7.0 or higher causes major damage over a large area.

Question 14

The chemical formula for Heavy Water is:

Accepted Answer

Correct Answer: D2O

Explanation: Heavy water is formally known as Deuterium Oxide (D2O). In heavy water, the hydrogen atoms are replaced by deuterium, a heavier isotope of hydrogen that contains a neutron. It is approximately 11% denser than ordinary water. It is primarily used as a neutron moderator in nuclear reactors to slow down neutrons.

Question 15

Which gas is filled in chips packets to prevent spoilage?

Accepted Answer

Correct Answer: Nitrogen

Explanation: Nitrogen gas is used to flush bags of potato chips and other snacks. This process is called nitrogen flushing. Nitrogen displaces oxygen, which would otherwise cause the fats in the chips to oxidize and turn rancid (stale). Nitrogen is inert, odorless, and tasteless, keeping the chips fresh and crispy while creating a cushion to prevent crushing.

Question 16

The study of the Universe is known as:

Accepted Answer

Correct Answer: Cosmology

Explanation: Cosmology is the scientific study of the origin, evolution, and eventual fate of the Universe. It involves physics and astronomy to understand concepts like the Big Bang Theory, dark matter, and black holes. Unlike astrology, which is a belief system, cosmology is based on observation, mathematics, and scientific evidence.

Question 17

Which planet is known as the 'Morning Star' or 'Evening Star'?

Accepted Answer

Correct Answer: Venus

Explanation: Venus is often called the Morning Star or Evening Star because it is the brightest object in the sky after the Sun and the Moon. It appears shortly before sunrise or shortly after sunset. It is not a star but a planet; its thick clouds reflect sunlight very effectively, making it shine brightly in our sky.

Question 18

Who invented the telephone?

Accepted Answer

Correct Answer: Alexander Graham Bell

Explanation: Alexander Graham Bell is credited with patenting the first practical telephone in 1876. He was interested in the transmission of sound because his mother and wife were deaf. His invention revolutionized global communication, allowing voice signals to be transmitted over wires. The first words spoken were, 'Mr. Watson, come here, I want to see you.'

Question 19

Which acid is present in Vinegar?

Accepted Answer

Correct Answer: Acetic Acid

Explanation: Vinegar consists chiefly of dilute Acetic Acid (ethanoic acid). It is produced by the fermentation of ethanol by acetic acid bacteria. The concentration of acetic acid in table vinegar typically ranges from 4% to 8%. It gives vinegar its sour taste and pungent smell, making it useful for cooking, pickling, and cleaning.

Question 20

The hardest part of the human body is:

Accepted Answer

Correct Answer: Tooth Enamel

Explanation: Tooth Enamel is the hardest and most highly mineralized substance in the human body. It covers the outer layer of teeth and protects them from decay and wear. It is even harder than bone because it contains a high percentage of hydroxyapatite crystals. However, unlike bone, enamel cannot repair itself once it is damaged.

Everyday Science MCQs