Everyday Science — Past Papers — Part 3 MCQs with Explanations

Earth’s gravity provides the force that keeps satellites in orbit. This gravitational force pulls the satellite toward Earth. The satellite’s forward motion makes it continuously fall around Earth rather than directly into it. Newton’s Law of Gravitation explains this gravitational attraction.

Bernoulli’s principle is based on conservation of energy in flowing fluids. P+1/2 ρv 2 +ρgh=constant For airplane wings: P = Pressure ρ (rho) = Density of air v = Speed of air g = Gravitational acceleration h = Height Higher air speed → Lower pressure Lower air speed → Higher pressure Pressure difference between the upper and lower surfaces creates lift. Lift acts upward and helps the airplane fly

Inventor: Thomas Alva Edison . Country: United States . Practical incandescent bulb: 1879 . Other contributions: Electric power, sound recording, motion pictures . Famous invention: Phonograph .

Mercury is the closest planet to the Sun , followed by Venus . Called an inner planet because it orbits inside Earth’s orbit. Number of moons: 0 (Mercury has no natural satellites ). Size: Smallest planet in the solar system. Nickname: Swift Planet , due to its fast orbit around the Sun (≈ 88 days per orbit ).

The Hubble Space Telescope is a joint project of NASA (USA) and ESA (European Space Agency). It was launched in 1990 into low Earth orbit. Scientists like John C. Mather contributed to its development and research. It is used for observing distant galaxies and space objects .

Earth is the third planet from the Sun in our solar system . The order of the planets starting closest to the Sun is: Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune

Saturn is famous for its prominent and beautiful ring system . Its rings are made mainly of ice particles, dust , and rock fragments . Additional information : It is the second-largest planet in the Solar System. It is often called the “ Ringed Planet .” Famous moon: Titan Orbital period: About 29.5 Earth years It is the sixth planet from the Sun .

A parameter is a value used to describe or define a system, model, or functio n. It usually remains constant for a particular situation. Example : In (y = mx + c), m and c can be parameters. Last updated: NA on 26-09-2026

Wavelength is the distance between successive wave crests . SI unit: Meter (m) Commonly measured in: Nanometers (nm) and Angstroms (Å) 1 nm = 10⁻⁹ m 1 Å = 10⁻¹⁰ m = 0.1 nm Visible light: Approximately 400–700 nm Last updated: 20-09-2026 by NA

Geology means the study of the Earth . It is also called Earth Science or Geoscience . Geology studies the formation, structure, composition , and history of Earth . It also examines the processes acting on Earth , such as earthquakes, volcanoes, and erosion . A person who studies geology is called a geologist .

The smallest unit of matter is an atom . Structure of an Atom Nucleus: The central part made of heavy protons and neutrons. Electrons: Tiny, light particles that circle the nucleus. Protons: Particles with a positive charge. Neutrons: Particles with no electrical charge

Position: 2nd planet from the Sun. Distance: About 108 million km from the Sun. Order: Mercury → Venus → Earth. Temperature: Hottest planet in the Solar System. Reason: Thick atmosphere traps heat through the greenhouse effect.

Legumes → plants with pods containing seeds, e.g., peanuts, lentils, chickpeas . Additional information : Scientific name → Arachis hypogaea Nutritional value → high protein and oil content Major producing countries → China, India, USA, Pakistan

Hydrogen and helium are the two lightest gases. Helium is the second most abundant element in the universe, after hydrogen . Helium has monatomic molecules. It is the lightest of all gases except hydrogen. Hydrogen is the lightest gas known. It provides the maximum lift for balloons due to its very low density . Last updated question 17-02-2026

Antarctic Notothenioids live in extremely cold waters. Includes Antarctic i cefish and Antarctic cod. Can live in seawater as cold as −2°C.

Discoverer: Alexander Fleming Year of discovery: 1928 Place: St. Mary's Hospital, London First patient treated with penicillin : Albert Alexander Date of first treatment: 12 February 1941

Astrology studies the supposed influence of stars and planets on human affairs. Origin: Ancient Mesopotamia (modern Iraq) . Developed by: Sumerians and Babylonians. Period : Around the 3rd–2nd millennia BCE.

Carbon dioxide (CO₂) is used in fire extinguishers . It extinguishes fire by displacing oxygen and cooling the burning material. CO₂ fire extinguishers are especially effective for electrical and flammable liquid fires. Carbon dioxide is a colorless and non-flammable gas. It leaves no residue after use.

Amylase break s down starch. Starch → Maltose + smaller sugars. Found in saliva and pancreatic juice. Salivary amylase starts starch digestion in the mouth

O⁻ (O Negative) is the universal donor blood group . It can be transfused to A, B, AB, and O blood groups. O⁻ blood lacks A, B, and Rh (D) antigens. Additional information : Universal Recipient : AB⁺ (AB Positive) ABO Blood Groups : A, B, AB, O Rh Types : Positive (+) and Negative (−) Total Common Blood Groups: 8 (A⁺, A⁻, B⁺, B⁻, AB⁺, AB⁻, O⁺, O⁻)

Nicolaus Copernicus proposed the heliocentric model. Heliocentric means the Sun is at the center. Earth and other planets revolve around the Sun. Proposed in the 16th century. Ptolemy supported th e geocentric model (Earth-centered).

Ice is less dense than water, so it floats. Archimedes’ Principle explains the buoyant force acting on floating ice. The buoyant force acts upward against gravity . Formula: FB = p Vg Key point: An object floats when buoyant force = its weight.

Vitamin C deficiency causes scurvy . It can cause bleeding/loose gums, easy bruising , and poor wound healing. Other signs include rough skin, corkscrew hair, and red spots around hair follicles . Rickets is mainly caused by Vitamin D deficiency.

Nitrogen (N₂) → 78% Additional information : Oxygen (O₂) → 21% Argon (Ar) → 0.93% Carbon dioxide (CO₂) → 0.04% (approximately) Other gases → Trace amounts

Heinrich Wilhelm Waldeyer coined the word "neuron" in 1891. He based it on the ancient Greek word for sinew or cord. Neuron theory/doctrine emerged at the end of the 19th century. Core claim — Nerve tissue = individual cells; each is a genetic, anatomic, functional, and trophic unit. Last updated by NA on 09-09-2026

Cumulonimbus clouds are tall, dense clouds associated with thunderstorms. They can produce hail, heavy rain, lightning , and strong winds . Hail forms when strong updrafts inside these storm clouds carry water droplets upward, where they freeze.

ECG stands for Electrocardiogram . It is a test that records the electrical activity of the heart . It is commonly used to check heart rate and rhythm .

A picosecond (ps) is equal to 10⁻¹² seconds . Additional information : Millisecond = 10⁻³ second Microsecond = 10⁻⁶ second Nanosecond = 10⁻⁹ second

Seismology is the study of earthquakes and seismic waves that move through and around the Earth. A seismologist is a scientist who studies earthquakes and seismic waves .

Myopia ( Nearsightedness ) is an eye defect in which near objects are clear but distant objects appear blurred. It occurs when the image forms in front of the retina instead of on it . It is corrected by using a concave ( diverging ) lens. The concave lens helps to shift the image back onto the retina.

Uranus is the planet in our solar system that rotates on its side Rotates on its side ( axial tilt ~98°), appearing to spin sideways 7th planet from the Sun 3rd-largest planet in the solar system Very cold and windy Has faint rings and more than two dozen small moons Last updated by NS on 06-09-2026 ​

Red blood cells lack a nucleus to maximize space for hemoglobin , which carries oxygen . More hemoglobin means more oxygen transport. This makes RBCs highly efficient for gas exchange. Lack of nucleus also gives them a flexible shape. This helps them pass through narrow blood capillaries.

Marie Curie is the only person to win Nobel Prizes in two different natural sciences . She won the Nobel Prize in Physics in 1903 . She won the Nobel Prize in Chemistry in 1911 . She was awarded for her pioneering work on radioactivity .

To convert Celsius to Kelvin , use: K = °C + 273 Given temperature = 37°C 37 + 273 = 310 K Additional information : 0°C = 273 K 100°C = 373 K

A tendon is not a bone; it is a strong connective tissue that connects muscles to bones. Tibia is the main bone of the lower leg . Femur is the thigh bone and the longest bone in the human body. Humerus is the bone of the upper arm .

The spinal cord is not part of the brain ; it is part of the central nervous system (CNS). The brain is broadly divided into forebrain, midbrain, and hindbrain . Pons and medulla oblongata are parts of the brainstem . The hindbrain includes the pons, medulla oblongata , and cerebellum .

Blood is red because of a protein called hemoglobin inside our red blood cells, Which contains iron that changes color when it binds to oxygen Last updated by NS on 5-09-2026

Stellar parallax is the apparent shift in the position of a nearby star as Earth moves around the Sun. It occurs because the star is observed from different positions in Earth's orbit. Astronomers use parallax to measure distances to relatively nearby stars. The greater the parallax , the closer the star is to Earth .

Pressure cookers cook food faster due to Gay-Lussac’s Law . This law states that pressure increases when temperature increases in a closed container. In a pressure cooker , steam is trapped, increasing pressure. Higher pressure raises the boiling point of water above 100°C . Food cooks at a higher temperature , so it cooks faster.

The mitochondrion is the primary site of oxidative phosphorylation in eukaryotic cells. Oxidative phosphorylation occurs mainly across the inner mitochondrial membrane . It produces most of the cell’s ATP (energy) through the electron transport chain and ATP synthase .