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65 interactive labs with 141 hands-on experiments you can drag, rotate and replay. Every number on screen comes from the real formula, so what you see is exactly what the exam expects. Each lab links to its formulas, common mistakes and practice questions.
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Physics
27 simulationsRay optics · Class 10 & Class 12Lens ray diagramEvery ray that leaves the tip of the object and passes through a lens meets at one point — the image — or appears to come from it. Three rays are enough to find that point: one parallel to the axis, one through the optical centre and one through the focus.Open simulation Current electricity · Class 10 & Class 12Circuit builderCurrent is the same everywhere in a series loop; voltage is the same across every branch of a parallel group. Almost every circuit question reduces to these two facts plus Ohm’s law.Open simulation Ray optics · Class 10 & Class 12Refraction and total internal reflectionLight changes speed when it enters a new medium, and that change of speed bends its path. Going into a denser medium it bends towards the normal; coming out it bends away.Open simulation The human eye and the colourful world · Class 10 & Class 12Human eye & defects of visionThe human eye functions like a camera: light enters through the transparent cornea, passes through the pupil, and is focused by the crystalline lens onto the light-sensitive retina.Open simulation Magnetic effects of electric current · Class 10 & Class 12Electric motor & Fleming’s left-hand ruleAn electric motor converts electrical energy into mechanical energy. When a rectangular coil of insulated copper wire is placed in a magnetic field and current flows through it, opposite forces act on its two parallel arms.Open simulation The human eye and the colourful world · Class 10 & Class 12Prism refraction, dispersion & rainbowWhen a beam of white light passes through a glass prism, it splits into a band of seven colors: Violet, Indigo, Blue, Green, Yellow, Orange, Red (VIBGYOR). This phenomenon is called dispersion.Open simulation Motion in a plane · Class 11Projectile motionA projectile moves under gravity alone: its horizontal velocity never changes, while its vertical velocity drops by g every second. Put those two independent motions together and you get a parabola.Open simulation Oscillations · Class 11Simple pendulumA pendulum is the classic example of simple harmonic motion — but only for small swings. The simulation solves the full equation θ″ = −(g/L) sin θ step by step, so you can see exactly when the textbook formula starts to drift.Open simulation Waves · Class 11Standing waves on a stringA standing wave forms when two identical waves travel in opposite directions and overlap. Some points never move (nodes) and some swing the most (antinodes).Open simulation Waves · Class 11 & Class 12Doppler effect in sound & sonic boomThe Doppler Effect is the apparent change in frequency or pitch of a wave perceived by an observer moving relative to the wave source.Open simulation 4 modesSystem of particles and rotational motion · Class 11Rotational dynamics and rollingRolling race, Rolling vs slipping, Moment of inertia, Toppling vs sliding.Open simulation 4 modesLaws of motion · Class 11Laws of motion, friction and pulleysIncline & friction, Atwood & pulleys, Block on block, Apparent weight (lift).Open simulation 3 modesWork, energy and power · centre of mass · Class 11Collisions, centre of mass and rockets1D collision, Oblique (2D) collision, Rocket (variable mass).Open simulation 3 modesLaws of motion · circular motion · Class 11Circular motion: banking and vertical circlesBanked road, Vertical circle, Conical pendulum.Open simulation 4 modesMechanical properties of fluids · Class 11Fluid mechanicsTorricelli tank, Bernoulli & Venturi, Stokes' law, Capillary rise.Open simulation 4 modesGravitation · Class 11Gravitation and orbitsKepler's laws, Orbit & escape speed, Variation of g, Tunnel through Earth.Open simulation 3 modesMechanical properties of solids · Class 11Elasticity: stress, strain and Young’s modulusStress–strain curve, Young's modulus, Wires in series & parallel.Open simulation 4 modesWork, energy and power · Class 11Work, energy and powerPotential energy curve, Loop-the-loop, Spring & friction, Work & power.Open simulation Electrostatics · Class 12Electric field linesField lines start on positive charges and end on negative ones. Where they bunch together the field is strong; where they spread out it is weak. They never cross, because the field has only one direction at each point.Open simulation 4 modesAlternating current · Class 12AC circuits, phasors and resonanceLCR & phasors, Resonance & Q-factor, Power factor, Transformer.Open simulation 4 modesWave optics · Class 12Wave optics: YDSE, diffraction and polarisationDouble slit (YDSE), Single-slit diffraction, Polaroids & Malus' law, Brewster angle.Open simulation 4 modesSemiconductor electronics · Class 12Semiconductors, diodes and logic gatesp-n junction, Rectifier, Zener regulator, Logic gates.Open simulation 3 modesDual nature of radiation and matter · Class 12Photoelectric effect and matter wavesPhotoelectric tube, Stopping potential vs ν, Matter waves.Open simulation 4 modesElectromagnetic induction · Class 12Electromagnetic inductionMagnet & coil (Lenz), Motional EMF, LR circuit, AC generator.Open simulation 4 modesElectrostatic potential and capacitance · Class 12Capacitors, dielectrics and RC circuitsParallel plate, Dielectric slab, RC charging, Series & parallel.Open simulation 3 modesAtoms · Class 12Atoms: Rutherford, Bohr and X-raysRutherford scattering, Bohr orbits, X-ray spectrum.Open simulation 3 modesNuclei · Class 12Nuclear physics: binding energy and radioactivityBinding energy curve, Radioactive decay, α, β, γ radiation.Open simulation
Chemistry
25 simulationsChemical bonding · Class 11Molecular shapes (VSEPR)VSEPR theory says electron pairs around a central atom push each other as far apart as possible. Count the bond pairs and lone pairs, and the shape follows.Open simulation States of matter · Class 11Ideal gas in a boxGas pressure is simply molecules hitting the walls. More molecules, faster molecules or a smaller box all mean more hits per second, and so more pressure.Open simulation Structure of atom · Class 11 & Class 12Hydrogen spectrum (Bohr model)In Bohr’s model the electron in hydrogen can only have certain energies, Eₙ = −13.6/n² eV. When it drops to a lower level, the energy difference leaves as one photon.Open simulation 4 modesEquilibrium · Class 11Chemical & ionic equilibrium / pH titrationLe Chatelier's Box, pH Titration & Indicators, Buffer & Henderson Eq., K_sp & Common Ion Effect.Open simulation 3 modesClassification of elements and periodicity · Class 11Periodic table & periodic trendsPeriodic Trends Heatmap, Z_eff & Slater’s Rules, Acidic & Basic Oxides.Open simulation 5 modesPractical chemistry · Class 11 & Class 12Qualitative salt analysis & test-tube simulatorBunsen Flame Test, Cation Group Separation, Anion Confirmatory Tests, Organic Functional Group Tests, Identify the unknown salt.Open simulation 3 modesPrinciples of organic chemistry · Class 11 & Class 12Stereochemistry & chirality studio3D Chirality & Enantiomers, R / S Configuration (CIP Rules), Newman & Sawhorse Conformations.Open simulation 3 modesThermodynamics · Class 11Thermodynamics: ΔG, entropy and Hess’s lawΔG and spontaneity, Hess's law, Entropy of the universe.Open simulation Chemical bonding · Class 11Molecular orbital theoryBond order is (bonding electrons − antibonding electrons) / 2. O₂ has two unpaired electrons in π*, so it is paramagnetic even though the Lewis structure looks like a complete double bond.Open simulation 2 modesSome basic concepts of chemistry · Class 11Mole concept and limiting reagentMolarity, molality, mole fraction, Limiting reagent.Open simulation Structure of atom · Class 11Atomic orbitals and quantum numbersn fixes the shell, l the subshell (0 = s, 1 = p, 2 = d), mₗ which orbital inside that subshell, and mₛ the spin. l cannot exceed n − 1, and mₗ runs from −l to +l.Open simulation States of matter · Class 11Real gases and liquefactionThe van der Waals equation corrects the ideal gas law for the volume of the molecules and for their attraction. A gas can be liquefied by pressure alone only below its critical temperature.Open simulation 4 modesElectrochemistry · Class 12Galvanic cell, Nernst & electrolysisDaniell cell (Zn-Cu), Nernst equation & EMF, Faraday's electrolysis, Conductance curves.Open simulation 3 modesChemical kinetics · Class 12Reaction kinetics & Arrhenius activationIntegrated Rate Laws & Half-life, Arrhenius & Catalyst Energy Barrier, Find the order from graphs.Open simulation 3 modesCoordination compounds · Class 12Coordination chemistry & crystal fieldOctahedral & Tetrahedral Splitting, Spectrochemical Series & Spin, d-d Absorption & Magnetism.Open simulation 3 modesHaloalkanes and haloarenes · Class 12Organic reaction mechanisms (SN1 & SN2)SN1 vs SN2 Substitution Race, E1 vs E2 Elimination (Saytzeff), Markovnikov vs Anti-Markovnikov.Open simulation 4 modesAldehydes, ketones and carboxylic acids · Class 12Carbonyl, Aldol & Cannizzaro reactionsNucleophilic Carbonyl Addition, Aldol Condensation, Cannizzaro Redox Disproportionation, Fischer Esterification.Open simulation 3 modesSolid state · Class 12Solid state crystal lattices & voidsUnit Cells: SC, BCC & FCC, Tetrahedral & Octahedral Voids, Schottky vs Frenkel Defects.Open simulation 3 modesSolutions · Class 12Raoult's law & colligative propertiesRaoult's Law & Azeotropes, 4 Colligative Properties, Van 't Hoff Factor & Dissociation.Open simulation 2 modesAmines · Class 12Amines: basicity and diazotisationBasicity order, Diazotisation.Open simulation Organic chemistry · Class 12Named organic reactionsEach named reaction is a short sequence. Play the frames rather than memorising only the product: the reagent, the intermediate and the carbon-count change are what the exam asks.Open simulation 2 modesSurface chemistry · Class 12Surface chemistryFreundlich and Langmuir, Tyndall and electrophoresis.Open simulation Coordination compounds · Class 12Coordination isomerism and namingIn octahedral [M(AA)₂b₂] the cis isomer has no mirror plane, so it exists as a pair of enantiomers. The trans isomer has a mirror plane and is optically inactive.Open simulation Electrochemistry · Class 12Electrochemical series and electrolysisE°cell = E°cathode − E°anode. A positive value means the cell reaction as written is spontaneous. In aqueous electrolysis, a cation above hydrogen usually liberates H₂ instead of depositing the metal.Open simulation 3 modesThe p-block elements · Class 12p-block trendsOxidising power of halogens, Allotropes of carbon, Oxoacids of P and S.Open simulation
Mathematics
5 simulationsTrigonometric functions · Class 10 & Class 11Unit circle trigonometryOn a circle of radius 1, the point at angle θ is (cos θ, sin θ). That single picture defines sin and cos for every angle, not just the ones in a right triangle.Open simulation Some applications of trigonometry · Class 10Heights and distances (Trigonometry applications)Trigonometry enables engineers and surveyors to calculate unreachable heights and distances without direct measurement.Open simulation Circles · Class 10Circles & tangent theorems (10.1 and 10.2)A tangent to a circle is a straight line that touches the circle at exactly one point, known as the point of contact.Open simulation Functions and graphs · Class 11 & Class 12Graph transformationsMost graphs in JEE are a familiar parent graph that has been shifted, stretched or flipped. Learn the four moves once and you can sketch y = −2(x − 3)² + 1 or y = 1/(x + 2) − 4 in seconds.Open simulation Coordinate geometry · Class 11 & Class 12Conic sections & eccentricityA conic section is the locus of a point P whose distance from a fixed point (focus S) is always a constant ratio e times its perpendicular distance from a fixed line (directrix): SP = e · PM. That single number e (the eccentricity) determines the curve’s entire shape and nature.Open simulation
Biology
8 simulationsCell: the unit of life · Class 8 & Class 9 & Class 11Cell explorerEvery living thing is made of cells, and each cell is a small factory. The nucleus holds the instructions, mitochondria release energy, ribosomes build proteins and the Golgi apparatus packs and ships them.Open simulation Cell cycle and cell division · Class 9 & Class 11Mitosis step by stepMitosis divides one cell into two identical cells with the same number of chromosomes. It is how you grow and how wounds heal.Open simulation Body fluids and circulation · Class 10 & Class 11Human heart and blood flowThe human heart is really two pumps side by side. The right side sends deoxygenated blood to the lungs, and the left side sends oxygenated blood to the rest of the body.Open simulation Excretory products and their elimination · Class 11 & Class 12Nephron & counter-current mechanismHuman kidneys can produce urine nearly four times concentrated than the initial filtrate (up to 1200 mOsm/L compared to 300 mOsm/L of blood plasma). This remarkable feat is achieved by the counter-current mechanism between Henle’s loop and the vasa recta.Open simulation Locomotion and movement · Class 11 & Class 12Sliding filament theory & muscle contractionContraction of a muscle fibre takes place by the sliding of thin filaments (Actin) over thick filaments (Myosin), proposed by Andrew Huxley and Hugh Huxley in the Sliding Filament Theory.Open simulation Neural control and coordination · Class 11 & Class 12Action potential & synaptic transmissionNeurons are excitable cells because their membranes are in a polarized state. In resting state, the axonal membrane is more permeable to K+ and nearly impermeable to Na+, establishing a resting potential of -70 mV.Open simulation Molecular basis of inheritance · Class 12DNA double helixDNA is two strands wound into a right-handed double helix. A always pairs with T using two hydrogen bonds, and G with C using three.Open simulation Principles of inheritance and variation · Class 12Mendelian dihybrid cross & Morgan’s linkageMendel’s dihybrid cross of round yellow seeds (RrYy × RrYy) demonstrates that traits segregate independently, producing 4 distinct phenotypes in a 9:3:3:1 ratio.Open simulation
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Questions about the lab
Are these simulations free?
Yes. All 65 simulations are free to use without an account, on a phone, tablet or computer.
How accurate are the numbers?
Every reading is calculated on your device from the same formulas used in NCERT and exam solutions. Where a picture is only illustrative (for example the shape of a diode curve), the page says so.
Which syllabuses do they cover?
They are organised by NCERT chapters for Class 8–12 and mapped to JEE Main, JEE Advanced and NEET. Many also match AP Physics, A-level, IB and GCSE topics — each page lists the exams it is useful for.
Can I link to one part of a simulation?
Yes. Multi-part labs have a link for each mode, for example /lab/rotational-motion-rolling#toppling opens straight to the toppling experiment.
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