Question 1

What is the main function of White Blood Cells (WBCs)?

Accepted Answer

Correct Answer: Fight Infection

Explanation: White Blood Cells (WBCs), or leukocytes, are the soldiers of the body's immune system. Their primary function is to detect and fight infections caused by bacteria, viruses, and fungi. They produce antibodies and destroy harmful foreign particles. Unlike red blood cells, WBCs have a nucleus and can move out of blood vessels to reach infected tissues.

Question 2

Which instrument is used to measure the purity of milk?

Accepted Answer

Correct Answer: Lactometer

Explanation: A Lactometer is used to check the purity of milk by measuring its specific gravity (density). It works on Archimedes' principle: a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. If water is added to milk, the density decreases, and the lactometer sinks deeper, indicating adulteration.

Question 3

The energy of the Sun is produced by which process?

Accepted Answer

Correct Answer: Nuclear Fusion

Explanation: The Sun generates energy through Nuclear Fusion, a process where hydrogen nuclei collide and fuse to form helium. This reaction releases an enormous amount of energy in the form of light and heat. It occurs in the Sun's core under extreme pressure and temperature. This energy travels to Earth and sustains almost all life on our planet.

Question 4

Which layer of the atmosphere is closest to the Earth?

Accepted Answer

Correct Answer: Troposphere

Explanation: The Troposphere is the lowest layer of Earth's atmosphere, extending from the surface up to about 10-15 km. It contains approximately 75% of the atmosphere's mass and 99% of its water vapor. Almost all weather phenomena, such as rain, clouds, and snow, occur in this layer. As you go higher in the troposphere, the temperature decreases.

Question 5

The deficiency of Iodine causes which disease?

Accepted Answer

Correct Answer: Goiter

Explanation: A deficiency of Iodine leads to Goiter, which is an enlargement of the thyroid gland in the neck. The thyroid gland uses iodine to produce hormones that regulate metabolism. When there isn't enough iodine, the gland works harder and swells up. This is why iodized salt is commonly used worldwide to prevent this condition and ensure proper thyroid function.

Question 6

Which blood group is known as the Universal Recipient?

Accepted Answer

Correct Answer: Group AB+

Explanation: Blood Group AB+ is known as the universal recipient because individuals with this blood type can receive red blood cells from any ABO blood group. This is because they have both A and B antigens on their red blood cells and no antibodies against A or B in their plasma. This makes them unique in emergency transfusion situations where specific blood types are unavailable.

Question 7

What is the S.I. unit of Electric Current?

Accepted Answer

Correct Answer: Ampere

Explanation: The SI unit of electric current is the Ampere (symbol: A), often shortened to 'amp'. It measures the rate of flow of electric charge past a point in a circuit. One ampere is equal to one coulomb of charge passing a point in one second. It is named after André-Marie Ampère, a French mathematician and physicist who is considered the father of electrodynamics.

Question 8

Which vitamin is found in abundance in Carrots?

Accepted Answer

Correct Answer: Vitamin A

Explanation: Carrots are rich in Beta-carotene, which the human body converts into Vitamin A. Vitamin A is essential for good vision, especially in low light, and helps prevent night blindness. It also maintains healthy skin and boosts the immune system. A deficiency in Vitamin A can lead to serious eye problems and increased susceptibility to infections.

Question 9

The chemical name of 'Dry Ice' is:

Accepted Answer

Correct Answer: Solid Carbon Dioxide

Explanation: Dry Ice is the solid form of Carbon Dioxide (CO2). It is called 'dry' because it sublimates, meaning it changes directly from a solid to a gas without passing through a liquid phase. It is extremely cold (-78.5°C) and is used for refrigeration, preserving frozen foods during transport, and creating fog effects in theaters.

Question 10

Which gas is used in the preparation of soda water?

Accepted Answer

Correct Answer: Carbon Dioxide

Explanation: Carbon Dioxide (CO2) is dissolved in water under high pressure to create soda water or carbonated beverages. When the pressure is released by opening the bottle, the gas escapes as bubbles, giving the drink its fizzy taste. It acts as a preservative and adds a sharp, acidic flavor to the drink. Without CO2, soft drinks would taste flat and sugary.

Question 11

Which part of the plant absorbs water and minerals from the soil?

Accepted Answer

Correct Answer: Roots

Explanation: Roots are the part of the plant that anchors it to the ground and absorbs water and dissolved minerals from the soil. They have tiny root hairs that increase the surface area for maximum absorption. The absorbed water and nutrients are then transported up to the stem and leaves.

Question 12

GPS stands for:

Accepted Answer

Correct Answer: Global Positioning System

Explanation: GPS stands for Global Positioning System. It is a satellite-based radionavigation system owned by the US government. It provides geolocation and time information to a GPS receiver anywhere on or near the Earth. It is essential for navigation in cars, planes, and smartphones.

Question 13

The nearest star to the Earth (other than the Sun) is:

Accepted Answer

Correct Answer: Proxima Centauri

Explanation: Proxima Centauri is the nearest known star to the Earth after the Sun. It is a red dwarf star located about 4.24 light-years away in the constellation Centaurus. It is part of the Alpha Centauri star system. Despite being the closest, it is too faint to be seen with the naked eye.

Question 14

Which vitamin helps in the absorption of Calcium?

Accepted Answer

Correct Answer: Vitamin D

Explanation: Vitamin D is essential for the absorption of Calcium in the gut. Without sufficient Vitamin D, the body cannot absorb enough calcium from the diet, leading to the body taking calcium from its own stores in the skeleton. This weakens existing bone and prevents the formation of strong, new bone.

Question 15

The pH value of pure water is:

Accepted Answer

Correct Answer: 7

Explanation: The pH of pure water is 7, which is considered neutral. The pH scale ranges from 0 to 14. Substances with a pH less than 7 are acidic, while those with a pH greater than 7 are basic (alkaline). Pure water is neither acidic nor basic, making it safe for consumption and life.

Question 16

Which gas is used in fire extinguishers?

Accepted Answer

Correct Answer: Carbon Dioxide

Explanation: Carbon Dioxide (CO2) is commonly used in fire extinguishers, especially for electrical fires and flammable liquid fires. CO2 works by displacing oxygen, which the fire needs to burn, and by cooling the fuel. Since CO2 is a gas, it does not leave a residue, making it ideal for delicate equipment.

Question 17

Bronze is an alloy of Copper and:

Accepted Answer

Correct Answer: Tin

Explanation: Bronze is an alloy consisting primarily of Copper, usually with Tin as the main additive. It is harder and more durable than copper alone. The Bronze Age was a significant period in human history when bronze tools and weapons replaced stone ones. It is also used in statues and medals.

Question 18

Which planet has the most moons?

Accepted Answer

Correct Answer: Saturn

Explanation: As of recent discoveries, Saturn holds the record for the planet with the most moons in our Solar System. It surpassed Jupiter with the confirmation of new moons, bringing its total to over 140. Titan is its largest and most famous moon. These moons vary greatly in size and composition.

Question 19

Light Year is a unit of:

Accepted Answer

Correct Answer: Distance

Explanation: A Light Year is a unit of astronomical distance. It represents the distance that light travels in a vacuum in one year (about 9.46 trillion kilometers). Because space is so vast, astronomers use light years to describe distances to stars and galaxies, as kilometers would result in unmanageably large numbers.

Question 20

Dialysis is used for the treatment of which organ failure?

Accepted Answer

Correct Answer: Kidney

Explanation: Dialysis is a medical treatment used when the Kidneys stop working properly (kidney failure). The kidneys are responsible for filtering waste and excess fluid from the blood. When they fail, dialysis takes over this function artificially, removing toxins and maintaining the balance of minerals in the blood.

Everyday Science MCQs