Everyday Science — All MCQs

Correct Answer: D

Wireless transmission can be done via All of these. Each listed statement describes a valid part of the same concept, so they apply together.

Correct Answer: B

Wisdom teeth normally grow between the age of 17-30. This follows from the structure and normal physiological function of the relevant organ, tissue, or body system.

Correct Answer: C

With the rise in temperature, metals conductivity Decreases. Its composition and chemical or physical behavior give it the stated classification or property.

Correct Answer: C

Wood is the main raw material used to manufacture paper. Wood fibers are processed into cellulose pulp, which is pressed and dried to form paper sheets.

Correct Answer: B

Ice floats because solid ice is less dense than liquid water. When water freezes, hydrogen bonding creates a more open crystal structure, so the same mass occupies more volume and stays above denser liquid water.

Correct Answer: D

Rickets is caused mainly by deficiency of vitamin D, which is needed for calcium and phosphate absorption and normal bone mineralisation. In children, deficiency leads to soft and weak bones, producing the disease called rickets.

Correct Answer: B

Laughing gas is nitrous oxide, chemically written as N2O. It has mild anaesthetic and analgesic effects and historically received the nickname because inhalation can produce euphoria or laughter.

Correct Answer: D

Humans normally have 12 pairs of ribs, making 24 ribs in total. The upper seven pairs are true ribs, the next three are false ribs, and the last two pairs are floating ribs.

Correct Answer: C

An average adult has about 5 litres of blood, though the exact amount varies with body size and sex. Therefore the scientifically accepted value is closer to 5 litres than to 7 or 8 litres.

Correct Answer: C

Carbon dioxide is a major greenhouse gas because it absorbs outgoing infrared radiation from Earth's surface. Increased CO2 from burning fossil fuels strengthens the greenhouse effect and contributes to global warming.

Correct Answer: A

The mixture has milk:water = 2:1 in 60 litres, so milk = 40 litres and water = 20 litres. To make milk:water = 1:2 while milk remains 40 litres, water must become 80 litres; additional water required = 80 - 20 = 60 litres.

Correct Answer: D

A light-year is a unit of distance, not time: it is the distance light travels in one year in vacuum. It is used in astronomy to describe very large distances between stars and galaxies.

Correct Answer: D

Pressure is measured in pascals in the SI system. One pascal equals one newton of force acting on one square metre of area, so it is a derived unit based on force and area.

Correct Answer: C

Mercury has the shortest orbit because it is the closest planet to the Sun. It completes one revolution around the Sun in about 88 Earth days, much faster than Earth or Neptune.

Correct Answer: B

Neptune is the farthest recognized planet from the Sun after Pluto was reclassified as a dwarf planet in 2006. Its great distance gives it a very long orbital period of about 165 Earth years.

Correct Answer: A

Venus is one of the brightest planets visible from Earth and is often called the morning or evening star. It appears bright because it is relatively near Earth and has highly reflective clouds.

Correct Answer: D

Dr. Abdus Salam won the Nobel Prize in Physics in 1979 for work on the electroweak unification theory. He shared the prize with Sheldon Glashow and Steven Weinberg and remains Pakistan's first Nobel laureate in science.

Correct Answer: B

Sulphur dioxide damages iron and steel structures because it contributes to acid rain and corrosive acidic conditions. In the presence of moisture, acidic pollutants accelerate rusting and deterioration of metals.

Correct Answer: C

Nitrogen is made usable for plants mainly after conversion into ammonia and then other nitrogen compounds through the nitrogen cycle. Nitrogen-fixing bacteria convert atmospheric nitrogen into ammonia, which can later become nitrates in soil.

Correct Answer: B

Vitamin E is closely associated with selenium because both act as antioxidants in the body and help protect cell membranes from oxidative damage. Selenium is not a vitamin itself, but it works with vitamin E in many biological functions.