General Science GK Notes

Physics, chemistry and biology facts frequently asked in exams.

67 topics2541 MCQs1911 previous-year questions278 quizzesUpdated 27 October 2026

General Science Questions General Science Quizzes

General Science in competitive exams means the school-level physics, chemistry and biology that examiners return to year after year. On this page the subject is broken into topics such as Units and Measurements, Light: Reflection and Refraction, Acids, Bases and Salts, Metals and Non-Metals, Nutrition, Vitamins and Deficiency Diseases, Diseases and Their Causes, and Scientific Instruments and Discoveries. Each topic is a short note that covers only what is asked, not the whole textbook chapter.

SSC CGL, SSC CHSL, RRB NTPC, RRB Group D and most state-level exams ask General Science as part of the General Awareness section. The questions are factual one-liners: the SI unit of a quantity, the instrument that measures it, the vitamin whose deficiency causes a disease, the common name of a chemical, the scientist behind a law. Railway and SSC papers lean on biology and everyday chemistry, so those topics deserve extra revision time.

Read the GK24 notes in syllabus order and finish each one with its practice MCQs before moving on. Previous-year questions on this page are tagged with the exam and year, so you can see how SSC and Railway papers actually phrase a fact. Once a few topics are done, use the mixed quiz sets to revise them together. Everything is in English and Hindi, so you can switch languages without losing your place.

Topic-wise notes

1
Units and Measurements
The SI system and its seven base units, derived and practical units, dimensional formulas, prefixes and the instruments used to measure, with the facts exams ask.
34 MCQs23 previous-year questions
2
Motion, Force and the Laws of Motion
Distance and displacement, speed, velocity and acceleration, the equations and graphs of motion, force, inertia, momentum and Newton's three laws, with the facts exams ask.
65 MCQs53 previous-year questions
3
Work, Energy and Power
The scientific meaning of work, the conditions in which it is zero, kinetic and potential energy, the work-energy theorem, conservation of energy, power, and the units exams ask about.
57 MCQs45 previous-year questions
4
Gravitation and Pressure
Newton's law of gravitation, the value and variation of g, mass against weight, escape velocity, thrust and pressure, Pascal's law, Archimedes' principle and atmospheric pressure, with the facts exams ask.
41 MCQs31 previous-year questions
5
Heat and Thermodynamics
Temperature scales, specific and latent heat, anomalous expansion of water, conduction, convection and radiation, and the laws of thermodynamics, with the facts SSC, Railway and State exams ask.
54 MCQs43 previous-year questions
6
Light: Reflection and Refraction
Laws of reflection, plane and spherical mirrors, the mirror and lens formulae, refraction and Snell's law, total internal reflection, dispersion and defects of vision, with the facts SSC, Railway and Defence exams ask.
74 MCQs67 previous-year questions
7
Sound and Waves
Nature of waves, sound as a longitudinal wave, wavelength frequency and speed, pitch loudness and quality, audible range, infrasonic and ultrasonic sound, echo, reverberation and SONAR, as asked in SSC, Railway and Defence exams.
62 MCQs56 previous-year questions
8
Electricity and Magnetism
Current, potential difference, Ohm's law, resistance, the heating effect, magnets, the magnetic effect of current, induction and domestic circuits, with the facts SSC, Railway and Defence exams ask.
125 MCQs118 previous-year questions
9
Atomic Structure and the Periodic Table
Discovery of the electron, proton and neutron, the Thomson, Rutherford and Bohr models, shells and the 2n squared rule, isotopes, and the periodic table from Dobereiner to Moseley, with exam facts.
85 MCQs79 previous-year questions
10
Chemical Bonding and Reactions
The octet rule, ionic, covalent, coordinate, metallic and hydrogen bonds, sigma and pi bonds, molecular shapes, and the five types of chemical reactions with corrosion, rancidity and catalysts, as exams ask them.
85 MCQs80 previous-year questions
11
Acids, Bases and Salts
Properties of acids and bases, indicators, the pH scale, neutralisation, acids in everyday substances and the common salts such as baking soda, washing soda, bleaching powder and plaster of Paris, with the facts exams ask.
80 MCQs73 previous-year questions
12
Metals and Non-Metals
Physical and chemical properties of metals and non-metals, the reactivity series, important ores and their metals, alloys, corrosion and its prevention.
67 MCQs60 previous-year questions
13
Carbon and Its Compounds
Covalent bonding and catenation in carbon, the allotropes diamond, graphite and fullerene, hydrocarbons and homologous series, functional groups, and the chemistry of ethanol and ethanoic acid.
78 MCQs72 previous-year questions
14
Everyday Chemistry and Common Names
Common and chemical names with formulas, the acids in food, soaps and detergents, hard water, colloids and the everyday uses examiners ask about.
61 MCQs53 previous-year questions
15
Cell and Tissues
Discovery of the cell, cell theory, prokaryotic and eukaryotic cells, the work of each organelle, and the plant and animal tissues exams ask about.
110 MCQs101 previous-year questions
16
Human Digestive and Respiratory Systems
The alimentary canal, the glands and enzymes of digestion, the path of air from nostril to alveolus, and the exchange of gases, with the facts exams ask.
47 MCQs38 previous-year questions
17
Circulatory and Excretory Systems
Blood and its parts, the four chambered heart, arteries and veins, blood groups, the kidney and the nephron, with the facts SSC, Railway and State exams ask.
52 MCQs43 previous-year questions
18
Nervous System and Endocrine Glands
The neuron, the parts of the brain, the spinal cord and reflex action, with the endocrine glands, their hormones and the diseases caused by their deficiency, as exams ask them.
35 MCQs26 previous-year questions
19
Nutrition, Vitamins and Deficiency Diseases
Macronutrients and micronutrients, the fat and water soluble vitamins with their chemical names and sources, mineral deficiency disorders, kwashiorkor and marasmus, and digestion.
46 MCQs35 previous-year questions
20
Diseases and Their Causes
Communicable and non-communicable diseases with their causative organisms, vectors, modes of spread, deficiency diseases, hereditary disorders and crop diseases, as exams ask them.
45 MCQs36 previous-year questions
21
Plant Biology: Photosynthesis and Reproduction
Photosynthesis and its light and dark reactions, pigments, C3, C4 and CAM plants, flower structure, pollination, double fertilisation, seeds, germination and plant hormones for competitive exams.
66 MCQs58 previous-year questions
22
Genetics and Evolution
Mendel's laws, DNA and chromosomes, common genetic disorders, and the theories of evolution from Lamarck and Darwin to the modern synthesis, with the facts SSC, Railway, Defence and State exams ask.
34 MCQs22 previous-year questions
23
Scientific Instruments and Discoveries
The instruments that measure each physical quantity and the scientists behind the major discoveries and inventions, arranged as the one-mark pairings competitive exams ask.
28 MCQs21 previous-year questions
24
States and Properties of Matter
Solid, liquid and gas and how they differ, change of state and latent heat, density, surface tension, viscosity and diffusion, the gas laws, plasma and the Bose-Einstein condensate.
42 MCQs34 previous-year questions
25
Elements, Compounds, Mixtures and Separation
Pure substances and mixtures, solutions, colloids and suspensions, the Tyndall effect and every method of separating mixtures, with the facts SSC, Railway and State exams ask.
49 MCQs38 previous-year questions
26
Fluids: Buoyancy, Viscosity and Surface Tension
Pressure in fluids and Pascal's law, Archimedes' principle and flotation, relative density, viscosity with Newton's and Stokes' laws, and surface tension with capillarity.
33 MCQs28 previous-year questions
27
Human Eye, Lenses and Dispersion of Light
Parts of the human eye, image formation and accommodation, the four defects of vision and their corrective lenses, the lens formula and power, dispersion by a prism, the rainbow and scattering.
63 MCQs55 previous-year questions
28
Radioactivity and Nuclear Energy
Radioactivity from Becquerel and the Curies to alpha, beta and gamma rays, half-life and units, fission and fusion, reactor parts, and India's three-stage nuclear programme.
25 MCQs15 previous-year questions
29
Semiconductors and Basic Electronics
Energy bands, intrinsic and extrinsic semiconductors, doping, the p-n junction, diodes, rectifiers, the transistor and logic gates, with the figures exams ask.
26 MCQs15 previous-year questions
30
Ores, Metallurgy and Alloys
Ores and their formulae, concentration, calcination and roasting, reduction and refining methods, and the composition and uses of the alloys exams ask about.
30 MCQs19 previous-year questions
31
Fuels and Combustion
Conditions and types of combustion, ignition temperature, the three zones of a flame, calorific values of fuels, coal and petroleum products, and fire extinguishers.
31 MCQs21 previous-year questions
32
Polymers, Plastics and Fibres
Monomers, polymerisation and the classification of polymers, the monomer and use of each important plastic, thermoplastic against thermosetting, vulcanisation, natural and synthetic fibres and biodegradable polymers.
23 MCQs13 previous-year questions
33
Classification of Living Organisms
Taxonomy and binomial nomenclature, the taxonomic hierarchy, the two to five kingdom systems, the features of Monera, Protista, Fungi, Plantae and Animalia, and where viruses and lichens fit.
25 MCQs15 previous-year questions
34
Animal Kingdom: Invertebrates and Vertebrates
The basis of animal classification, the phyla from Porifera to Chordata with their features and examples, and the seven classes of vertebrates with the exceptions exams ask.
44 MCQs32 previous-year questions
35
Microorganisms: Bacteria, Viruses and Fungi
Bacteria, viruses, fungi, protozoa and algae: their structure, the diseases they cause and their carriers, nitrogen fixation, fermentation, antibiotics and the other uses of microbes.
40 MCQs28 previous-year questions
36
Skeletal and Muscular System
Bones of the human body, axial and appendicular skeleton, joints, teeth, the three kinds of muscle, muscle contraction and bone disorders, with exam-ready numbers and names.
20 MCQs11 previous-year questions
37
Human Reproduction and Reproductive Health
Male and female reproductive systems, gamete formation, the menstrual cycle, fertilisation, implantation, pregnancy and lactation, with contraception, the MTP Act, STIs and assisted reproduction.
23 MCQs12 previous-year questions
38
Blood Groups, Immunity and Vaccines
The composition of blood, the ABO and Rh blood groups with donor and recipient rules, clotting, innate and acquired immunity, antibodies, and the types of vaccines with the immunisation programme.
24 MCQs13 previous-year questions
39
Biotechnology and Its Applications
Tools of recombinant DNA technology, Bt crops and Golden Rice, tissue culture, recombinant insulin and vaccines, gene therapy, DNA fingerprinting, gene editing and the bodies that regulate biotechnology in India.
19 MCQs7 previous-year questions
40
Plant Hormones and Economically Important Plants
Auxin, gibberellin, cytokinin, abscisic acid and ethylene with their functions and uses, and the economically important plants: fibres, spices, beverages, drugs and the plant part each product comes from.
25 MCQs15 previous-year questions
41
Space Science: Stars, Galaxies and Satellites
How stars shine and die, the light year and the parsec, galaxies and the Big Bang, and the orbits and uses of artificial satellites, with India's landmark missions.
25 MCQs18 previous-year questions
42
Famous Scientists and Their Laws
Scientists matched with the laws, principles and discoveries named after them, from Newton and Archimedes to Mendel, Einstein and the Indian scientists, as exams ask them.
19 MCQs10 previous-year questions
43
Plant Kingdom: Algae to Angiosperms
Classification of the plant kingdom from algae and bryophytes to pteridophytes, gymnosperms and angiosperms, with their features, examples, uses and the monocot and dicot difference exams ask.
20 MCQs9 previous-year questions
44
Important Gases and Their Uses
Properties, preparation and uses of hydrogen, oxygen, nitrogen, carbon dioxide, ammonia, chlorine, methane, the noble gases and common fuel gas mixtures.
27 MCQs20 previous-year questions
45
Human Body: Important Facts
Important facts about the human body for exams: bones, muscles, blood, heart, lungs, digestion, brain, glands and kidneys, with the superlatives and numbers papers ask.
15 MCQs3 previous-year questions
46
Electromagnetic Waves and the Spectrum
Electromagnetic waves and the spectrum for exams: properties, speed in vacuum, the order from radio waves to gamma rays, wavelength ranges, discoverers and everyday uses.
39 MCQs28 previous-year questions
47
Scientific Names of Plants and Animals
Binomial nomenclature and its rules with the scientific names of common animals, crops, trees and the national symbols of India that competitive exams ask.
15 MCQs4 previous-year questions
48
Branches of Science and Their Fields of Study
The branches of science and what each studies, from mycology and ornithology to seismology, pedology and cryogenics, with the look-alike pairs and the founders of each science.
13 MCQs1 previous-year questions
49
Simple Machines: Levers, Pulleys and Inclined Planes
Mechanical advantage, velocity ratio and efficiency, the three classes of lever, fixed and movable pulleys, the inclined plane, the wedge, the screw and the wheel and axle.
15 MCQs8 previous-year questions
50
Chemistry of Water: Hard Water, Heavy Water and Purification
Composition and anomalous properties of water, temporary and permanent hardness with the methods of softening, heavy water and its use as a moderator, and the stages of water purification.
21 MCQs11 previous-year questions
51
Sense Organs: Eye, Ear, Nose, Tongue and Skin
Structure and working of the five sense organs: the coats of the eye, rods and cones and defects of vision, the three parts of the ear, olfactory and gustatory receptors, and the layers and receptors of the skin.
17 MCQs8 previous-year questions
52
Electrochemistry: Electrolysis, Electroplating and Batteries
Electrolytes and electrolysis, the electrodes and their reactions, Faraday's laws, electroplating, primary and secondary cells, the lead-acid battery, fuel cells and the prevention of corrosion.
19 MCQs9 previous-year questions
53
Morphology of Flowering Plants: Root, Stem, Leaf and Flower
Root and shoot systems, modifications of root, stem and leaf, venation and phyllotaxy, inflorescence, the parts of a flower, aestivation, placentation, and the main types of fruit and seed.
27 MCQs16 previous-year questions
54
Friction and Circular Motion
Friction and circular motion for SSC, Railway and Defence exams: types of friction, the laws, angle of repose, centripetal and centrifugal force, banking of roads and the formulas asked.
25 MCQs17 previous-year questions
55
Cell Division: Mitosis and Meiosis
Cell division for SSC, Railway, NDA and State exams: the cell cycle and its phases, the four stages of mitosis, the five sub-stages of prophase I, meiosis I and II, and the significance of each division.
19 MCQs7 previous-year questions
56
Gas Laws and the Kinetic Theory of Gases
Gas laws and the kinetic theory for SSC, Railway, Defence and State exams: Boyle, Charles, Gay-Lussac, Avogadro, Dalton and Graham, the ideal gas equation, molecular speeds and specific heats.
18 MCQs8 previous-year questions
57
Plant Diseases and Their Causes
Fungal, bacterial, viral, phytoplasmal and nematode diseases of crops, the deficiency diseases of plants, their vectors and the common methods of control.
12 MCQs2 previous-year questions
58
Modern Physics: Photoelectric Effect, Lasers and Superconductivity
The photoelectric effect and Einstein's equation, how a laser works and its properties and uses, and superconductivity with the Meissner effect and its applications.
16 MCQs6 previous-year questions
59
Atoms and Molecules: Laws of Chemical Combination and the Mole Concept
The laws of conservation of mass, definite and multiple proportions, Dalton's atomic theory, atomic and molecular mass, formula unit mass, valency and the mole with the Avogadro number, worked for exams.
35 MCQs27 previous-year questions
60
Plant Physiology: Transpiration, Transport and Respiration
Absorption of water, ascent of sap, transpiration and stomata, translocation of food through the phloem and respiration in plants, with the facts SSC, Railway, State and Defence exams ask.
29 MCQs18 previous-year questions
61
Elasticity: Stress, Strain and Hooke's Law
Elastic and plastic behaviour, the three kinds of stress and strain, Hooke's law, Young's modulus, bulk modulus and rigidity, Poisson's ratio and the stress-strain curve, with the facts SSC, Railway and Defence exams ask.
20 MCQs11 previous-year questions
62
Food Preservation, Adulteration and Food Safety
Methods of food preservation, Class I and Class II preservatives, common adulterants and their tests, the diseases they cause, and the FSSAI framework under the Act of 2006.
14 MCQs4 previous-year questions
63
Industrial Chemistry: Glass, Cement, Fertilisers and Explosives
Types of glass and the oxides that colour them, the raw materials and setting of Portland cement, the nitrogen, phosphate and potash fertilisers with their nutrient content, and the low and high explosives.
34 MCQs26 previous-year questions
64
Centre of Gravity, Torque and Equilibrium
Centre of mass and centre of gravity, torque and its unit, couples and the principle of moments, levers, the conditions of equilibrium and stable, unstable and neutral equilibrium with everyday examples.
18 MCQs8 previous-year questions
65
Economic Zoology: Sericulture, Apiculture and Lac Culture
Silkworms and the four silks of India, honey bee species and the bee colony, the lac insect and its host plants, with the institutes, terms and facts exams ask.
15 MCQs3 previous-year questions
66
Oscillations: Simple Harmonic Motion and the Pendulum
Periodic and oscillatory motion, the equations and energy of simple harmonic motion, the laws of the simple pendulum, second's pendulum, damping and resonance.
21 MCQs13 previous-year questions
67
Interference, Diffraction and Polarisation of Light
Wave nature of light for exams: Young's double slit experiment, fringe width, thin film colours, diffraction, resolving power, Polaroid, Brewster's law and Malus's law.
12 MCQs4 previous-year questions

Frequently Asked Questions

Which General Science topics are asked most in RRB NTPC and Group D?

Biology and everyday chemistry carry the most weight in Railway papers. Expect questions on vitamins and deficiency diseases, human body systems, diseases and their causes, common names of chemicals, acids and bases, and metals and non-metals. In physics, units and measurements, light, sound and simple electricity questions repeat often. Cover these topics first, then move to the rest of the syllabus.

How many General Science questions come in SSC CGL Tier 1?

The General Awareness section of SSC CGL Tier 1 has 25 questions, and science usually takes a visible share of them, often somewhere around 5 to 8, though the split changes from paper to paper. The questions are direct and factual, so a small number of well-revised topics can fetch most of these marks.

Do I need to study NCERT books for General Science GK?

NCERT science books from Class 6 to 10 are the base most toppers use, but exams do not ask derivations or numericals. What you need is the factual layer: definitions, units, laws, examples and common names. Topic-wise notes that pick out this layer save time, and you can go back to the NCERT chapter only for a concept that stays unclear.

Is General Science asked in Banking exams like IBPS PO and SBI Clerk?

Not as a separate section. IBPS and SBI papers test General Awareness with a banking and current-affairs focus, and science appears only through current affairs, for example a new ISRO mission or a health-related scheme. If you are preparing for Banking alone, keep science light; if you are also writing SSC or Railway exams, the full syllabus matters.

What kind of physics questions are asked in competitive exams?

Physics questions in SSC and Railway exams are conceptual one-liners rather than calculations. Typical asks include the SI unit of a quantity, which law explains an everyday event, why the sky looks blue, what a particular instrument measures, or which type of lens corrects a given eye defect. Learn the units, laws, instruments and their discoverers as a list and practise them with MCQs.

How should I revise General Science before the exam?

Keep a one-page list per topic of units, instruments, vitamins, diseases, common names and scientist-law pairs, and revise it rather than rereading full notes. Attempt mixed quiz sets under time so that facts from physics, chemistry and biology come up together, exactly as they do in the paper. Note every wrong answer and revisit that topic's note the same day.