Introduction to General Science Competitive Exams
100 questions · General Science
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Question 1 of 100
The approximate speed of sound in air at room temperature is:
ExplanationSound travels much slower than light, about 343 metres per second in air.
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Question 2 of 100
Photosynthesis in plant cells takes place mainly in the:
ExplanationChloroplasts contain chlorophyll and carry out photosynthesis.
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Question 3 of 100
Penicillin, the first widely used antibiotic, was discovered by:
ExplanationFleming discovered penicillin from mould in 1928; it targets bacteria, not viruses.
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Question 4 of 100
The instrument used to measure humidity in the air is the:
ExplanationHygrometers measure the amount of water vapour (moisture) in the air.
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Question 5 of 100
Coal, oil and natural gas are classified as:
ExplanationFossil fuels formed over millions of years and are finite in supply.
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Question 6 of 100
A bond formed by the transfer of electrons between atoms is called:
ExplanationIonic bonds form between oppositely charged ions after electron transfer.
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Question 7 of 100
The instrument used to measure atmospheric pressure is the:
ExplanationBarometers measure air pressure, useful in weather forecasting.
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Question 8 of 100
Acidic substances turn blue litmus paper:
ExplanationThis is a standard test to identify acids.
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Question 9 of 100
The Theory of Evolution by Natural Selection was proposed by:
ExplanationDarwin's 1859 work "On the Origin of Species" introduced natural selection.
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Question 10 of 100
Organic chemistry is mainly the study of compounds containing:
ExplanationOrganic chemistry focuses on carbon-based compounds.
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Question 11 of 100
Ohm's Law states that V equals:
ExplanationVoltage equals current multiplied by resistance (V = IR).
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Question 12 of 100
Isotopes of an element have the same atomic number but different:
ExplanationIsotopes differ in neutron count, hence differing mass numbers.
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Question 13 of 100
A deficiency of Vitamin C in the diet commonly causes:
ExplanationVitamin C deficiency leads to scurvy, affecting gums and connective tissue.
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Question 14 of 100
The SI unit of time is the:
ExplanationThe second (s) is the SI base unit of time.
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Question 15 of 100
Basic (alkaline) substances turn red litmus paper:
ExplanationThis is a standard test to identify bases/alkalis.
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Question 16 of 100
The enzyme pepsin, which digests proteins, works best in the:
ExplanationPepsin functions in the acidic environment of the stomach.
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Question 17 of 100
A polymer such as plastic is made up of many repeating units called:
ExplanationPolymers are long chains built from smaller repeating monomer units.
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Question 18 of 100
Carbon dioxide and methane are examples of gases that cause the:
ExplanationThese gases trap heat in the atmosphere, warming the planet.
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Question 19 of 100
The modern periodic table arranges elements in order of increasing:
ExplanationMendeleev used atomic mass; the modern table uses atomic number.
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Question 20 of 100
A catalyst is a substance that speeds up a reaction while:
ExplanationCatalysts lower activation energy without being used up.
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Question 21 of 100
Osmosis is the movement of water molecules across a semi-permeable membrane from an area of:
ExplanationWater moves toward the side with more dissolved solute (lower water potential).
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Question 22 of 100
Avogadro's number, approximately 6.022x10^23, represents the number of particles in:
ExplanationA mole always contains Avogadro's number of particles.
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Question 23 of 100
Sound waves cannot travel through:
ExplanationSound needs a material medium; it cannot travel in a vacuum.
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Question 24 of 100
Counting outward from the Sun, which planet comes first?
ExplanationMercury is the closest planet to the Sun.
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Question 25 of 100
The largest planet in our Solar System is:
ExplanationJupiter is the largest planet by both mass and volume.
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Question 26 of 100
The theory describing the origin of the universe from a single expanding point is the:
ExplanationThe universe is believed to have begun expanding from an extremely dense state.
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Question 27 of 100
The chemical formula for water is:
ExplanationWater is composed of two hydrogen atoms and one oxygen atom.
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Question 28 of 100
The SI unit of temperature is the:
ExplanationKelvin (K) is the SI base unit; 0 K is absolute zero.
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Question 29 of 100
The practical incandescent electric light bulb is credited to:
ExplanationEdison developed a commercially practical long-lasting light bulb.
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Question 30 of 100
The SI unit of mass is the:
ExplanationThe kilogram (kg) is the SI base unit of mass.
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Question 31 of 100
Solar and wind power are examples of:
ExplanationThese natural sources replenish continuously and do not run out.
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Question 32 of 100
Red blood cells carry oxygen mainly using the protein:
ExplanationHemoglobin binds oxygen in red blood cells for transport around the body.
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Question 33 of 100
The SI unit of power is the:
ExplanationPower is the rate of doing work; 1 W = 1 J/s.
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Question 34 of 100
A normal human blood pressure reading is approximately:
Explanation120/80 mmHg (systolic/diastolic) is considered a normal healthy reading.
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Question 35 of 100
Radioactivity was discovered through the pioneering work of:
ExplanationMarie and Pierre Curie's research on radioactivity won Nobel Prizes.
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Question 36 of 100
The SI unit of frequency is the:
ExplanationFrequency is cycles per second, named after Heinrich Hertz.
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Question 37 of 100
A normal human body cell contains how many chromosomes?
ExplanationHumans have 23 pairs of chromosomes, totalling 46 in body cells.
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Question 38 of 100
The correct order of steps in the scientific method is:
ExplanationScience proceeds by observing, forming a hypothesis, testing, then concluding.
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Question 39 of 100
The chemical formula of methane gas is:
ExplanationMethane is the simplest hydrocarbon, with one carbon and four hydrogens.
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Question 40 of 100
The basic functional unit of the nervous system is the:
ExplanationNeurons transmit electrical and chemical signals throughout the body.
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Question 41 of 100
In a chemical reaction, oxidation refers to the:
ExplanationOxidation is loss of electrons; reduction is gain of electrons (OIL RIG).
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Question 42 of 100
The organelle known as the "powerhouse of the cell" is the:
ExplanationMitochondria generate most of the cell's ATP (energy).
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Question 43 of 100
"Every action has an equal and opposite reaction" is Newton's:
ExplanationThis is the statement of Newton's Third Law of Motion.
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Question 44 of 100
Archimedes' Principle relates to the buoyant force on a body and the:
ExplanationBuoyant force equals the weight of the fluid displaced by the body.
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Question 45 of 100
The cell was first discovered and named by:
ExplanationHooke observed cork cells under a microscope in 1665.
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Question 46 of 100
The Sun generates energy mainly through:
ExplanationHydrogen nuclei fuse into helium, releasing enormous energy.
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Question 47 of 100
The hormone that regulates blood sugar and is produced by the pancreas is:
ExplanationInsulin helps cells absorb glucose, lowering blood sugar levels.
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Question 48 of 100
The SI unit of work and energy is the:
ExplanationNamed after James Prescott Joule.
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Question 49 of 100
In photosynthesis, plants convert carbon dioxide and water into glucose and:
ExplanationPhotosynthesis releases oxygen as a byproduct using sunlight energy.
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Question 50 of 100
The SI unit of length is the:
ExplanationThe metre (m) is the SI base unit of length.
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Question 51 of 100
The Theory of Relativity was proposed by:
ExplanationEinstein's theory revolutionised ideas about space, time and gravity.
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Question 52 of 100
The positively charged particle inside an atom is the:
ExplanationProtons carry a positive charge and reside in the nucleus.
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Question 53 of 100
The Doppler Effect refers to the apparent change in:
ExplanationFrequency appears to change when source and observer move relative to each other.
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Question 54 of 100
A convex lens is commonly used to correct:
ExplanationConvex (converging) lenses correct hypermetropia (long-sightedness).
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Question 55 of 100
Galileo Galilei is best known for improving which instrument for astronomy?
ExplanationGalileo used an improved telescope to make key astronomical observations.
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Question 56 of 100
The hardest naturally occurring substance is:
ExplanationDiamond is a crystalline form of carbon, extremely hard.
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Question 57 of 100
The human organs primarily responsible for filtering blood and forming urine are the:
ExplanationKidneys filter waste from blood to form urine, part of excretion.
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Question 58 of 100
The main human blood groups are:
ExplanationThe ABO system classifies blood into these four main groups.
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Question 59 of 100
The ozone layer, which protects Earth from harmful UV rays, is located in the:
ExplanationOzone concentration peaks in the stratosphere, shielding life from UV radiation.
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Question 60 of 100
The double helix structure of DNA was discovered by:
ExplanationJames Watson and Francis Crick described DNA's structure in 1953.
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Question 61 of 100
Pascal's Law states that pressure applied to an enclosed fluid is:
ExplanationThis principle underlies hydraulic systems such as car brakes.
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Question 62 of 100
The smallest particle of an element that retains its properties is the:
ExplanationAn atom is the basic building block of all elements.
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Question 63 of 100
Wireless radio communication across the Atlantic was pioneered by:
ExplanationMarconi sent the first transatlantic radio signal in 1901.
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Question 64 of 100
Rusting of iron is an example of:
ExplanationIron reacts with oxygen and moisture to form iron oxide (rust).
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Question 65 of 100
The largest organ of the human body is the:
ExplanationThe skin is the largest organ, covering the whole body.
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Question 66 of 100
The negatively charged particle in an atom is the:
ExplanationElectrons orbit the nucleus and carry a negative charge.
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Question 67 of 100
The SI unit of force is the:
ExplanationNamed after Isaac Newton; 1 N = 1 kg.m/s2.
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Question 68 of 100
Density of a substance is defined as:
ExplanationDensity = mass divided by volume, usually in kg/m^3.
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Question 69 of 100
The instrument used to record the intensity of earthquakes is the:
ExplanationSeismographs detect and record ground motion caused by earthquakes.
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Question 70 of 100
The microscope is primarily used to observe:
ExplanationMicroscopes magnify tiny objects invisible to the naked eye.
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Question 71 of 100
Electrolysis of water produces hydrogen gas and:
ExplanationAn electric current splits water into hydrogen and oxygen gas.
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Question 72 of 100
Carl Linnaeus is widely known as the father of:
ExplanationLinnaeus developed the binomial system of naming and classifying organisms.
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Question 73 of 100
According to Newton's Second Law, force equals:
ExplanationF = m x a is the mathematical form of the Second Law.
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Question 74 of 100
The telephone was invented by:
ExplanationBell patented the telephone in 1876.
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Question 75 of 100
The most abundant gas in the Earth's atmosphere is:
ExplanationNitrogen makes up about 78% of the atmosphere by volume.
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Question 76 of 100
Pure water has a pH value of approximately:
ExplanationA pH of 7 is neutral; below 7 is acidic, above 7 is basic.
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Question 77 of 100
The approximate speed of light in vacuum is:
ExplanationLight travels at about 3x10^8 metres per second in vacuum.
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Question 78 of 100
The approximate value of acceleration due to gravity on Earth is:
ExplanationStandard gravity is about 9.8 m/s^2 near Earth's surface.
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Question 79 of 100
A deficiency of Vitamin D in children commonly causes:
ExplanationVitamin D deficiency weakens bones, causing rickets in children.
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Question 80 of 100
The green pigment in plants responsible for photosynthesis is:
ExplanationChlorophyll absorbs sunlight for photosynthesis, giving plants their green colour.
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Question 81 of 100
A lever, pulley and inclined plane are all examples of:
ExplanationSimple machines make work easier by changing force or direction.
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Question 82 of 100
The human heart has how many chambers?
ExplanationTwo atria and two ventricles make up the four chambers.
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Question 83 of 100
Newton's First Law of Motion is also called the law of:
ExplanationA body stays at rest or in uniform motion unless acted on by a force.
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Question 84 of 100
Cellular respiration releases energy from the breakdown of:
ExplanationGlucose is broken down in respiration to release usable energy (ATP).
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Question 85 of 100
The instrument used to measure temperature is the:
ExplanationThermometers measure temperature using scales such as Celsius or Fahrenheit.
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Question 86 of 100
The modern periodic table's precursor, arranging elements by atomic mass, was created by:
ExplanationMendeleev's 1869 table grouped elements and predicted undiscovered ones.
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Question 87 of 100
An echo is produced due to the:
ExplanationSound waves bounce off a hard surface and return as an echo.
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Question 88 of 100
The laws of inheritance were first proposed by, earning him the title "Father of Genetics":
ExplanationMendel's pea plant experiments founded the science of genetics.
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Question 89 of 100
The international research effort that mapped the complete set of human genes is the:
ExplanationCompleted in 2003, it sequenced nearly all human DNA.
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Question 90 of 100
The particle in the nucleus with no electric charge is the:
ExplanationNeutrons are electrically neutral particles found in the nucleus.
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Question 91 of 100
Reduction in a chemical reaction refers to the:
ExplanationReduction is the gain of electrons by a reactant.
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Question 92 of 100
Which branch of science studies the composition and properties of substances?
ExplanationChemistry deals with matter's composition, structure and reactions.
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Question 93 of 100
The basic structural and functional unit of life is the:
ExplanationAll living organisms are composed of one or more cells.
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Question 94 of 100
The photoelectric effect, explained by Einstein, shows that light behaves as:
ExplanationEinstein explained the effect using the idea of light quanta, or photons.
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Question 95 of 100
The adult human skeleton normally contains how many bones?
ExplanationAn adult human body has 206 bones (infants have more, which fuse).
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Question 96 of 100
The chemical name for common table salt is:
ExplanationTable salt is NaCl, sodium chloride.
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Question 97 of 100
The blood cells primarily responsible for fighting infection are:
ExplanationWhite blood cells (leukocytes) are part of the immune system.
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Question 98 of 100
The law of universal gravitation was formulated by:
ExplanationNewton described how every mass attracts every other mass.
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Question 99 of 100
Noble gases, found in Group 18, are generally known for being:
ExplanationTheir full outer electron shell makes them largely unreactive.
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Question 100 of 100
The SI unit of electric current is the:
ExplanationCurrent is measured in Amperes (A), named after Andre-Marie Ampere.
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