Interactive Physics Simulations for Students | Shikkha Web

Grade 8–12

Refraction of light

Change the angle and watch light bend. Snell's law, refractive index, critical angle and total internal reflection, explained simply with worked examples.

Grade 9–12

Ohm's law

Adjust voltage and resistance and watch the current change. Ohm's law formula, V-I graph, series and parallel resistors, with solved problems.

Grade 11

Projectile motion

Set the launch angle and speed and trace the path. Time of flight, maximum height and range formulas, why 45° goes farthest, with solved numbers.

Grade 9–11

Simple pendulum

Change length and gravity and time the swing. Simple pendulum period T = 2π√(L/g), SHM, energy conservation and finding g, with solved numbers.

Grade 10–12

Electric field

Drop positive and negative charges and watch the field lines form. Coulomb's law, E = kq/r², units and field-line rules, with solved examples.

Grade 11–12

Wave interference

Move two wave sources and watch bright and dark fringes appear. Superposition, constructive vs destructive conditions, fringe width, solved examples.

Grade 9–11

Free Fall

What is free fall? Drop a coin and a feather with and without air. Learn the free fall formulas for time, velocity and height (g = 9.8 m/s²) with worked examples.

Grade 10–12

Lens ray diagrams

Interactive convex and concave lens ray diagrams: drag the object through all six cases, see the three principal rays, and read u, v, f, magnification and power live.

Grade 9–11

Newton's Laws of Motion

Newton's laws of motion explained with an interactive cart: inertia, F = ma, momentum, impulse and action–reaction pairs, with examples and worked problems.

Grade 10–12

Spherical mirror ray diagrams

Drag an object in front of a concave, convex or plane mirror and watch the rays find the image. Mirror formula, magnification, all six cases, solved problems.

Grade 10–12

Electromagnetic Induction

What is electromagnetic induction? Drag a bar magnet through a coil and watch a centre-zero galvanometer. Learn Faraday's law e = −N dΦ/dt and Lenz's law with worked examples.

Grade 9–11

Conservation of Momentum and Collisions

What is the conservation of momentum? Collide two carts and drag the restitution slider from a sticking e = 0 to a bouncy e = 1. See momentum and kinetic-energy bars update live, with worked examples.

Grade 9–11

Work, Energy and Power

What is work, and what are the formulas for kinetic and potential energy and power? Release a cart on a curved track, watch energy turn to heat, with worked examples.

Grade 9–11

Inclined Plane

How does a block’s weight split on a slope, what is the angle of repose, and when does friction hold a block still or let it slide? Change the angle yourself and watch the force-arrow diagram.

Grade 9–11

Uniform circular motion

Whirl a ball on a string and read ω, T, a = v²/r and F = mv²/r live. Cut the string to see it fly off tangentially, then try banked curves with solved numbers.

Grade 8–10

Transverse and Longitudinal Waves

See a rope wave and a slinky or sound wave driven by one source. Learn crest, trough, compression, rarefaction, wavelength, v = fλ and why particles never travel with the wave, with solved problems.

Grade 9–11

Levers and moments

Slide weights on a seesaw and watch the moment M = F × d on each side. Learn the principle of moments, three classes of lever and mechanical advantage, with solved problems.

Grade 9–11

Centre of mass

Drag masses along a rod or plate and watch the centre of mass x = Σmx/Σm move. Find the balance point, see when a bus topples, and learn stable, unstable and neutral equilibrium with solved problems.

Grade 9–11

Spring-mass SHM

Run a mass on a spring in simple harmonic motion. Explore Hooke’s law, T = 2π√(m/k), energy swapping, springs in series and parallel, with worked problems and exam practice.

Grade 9–11

Vector addition: triangle and parallelogram laws

Add two vectors by the triangle and parallelogram laws, split them into components, then test a river-crossing boat and a walker with an umbrella. With solved problems.

Grade 9–11

Relative velocity: trains and river crossing

Play with two trains and a swimmer crossing a river. Learn relative speed, train crossing time, heading angle, drift, shortest time vs shortest path, with solved problems.

Grade 11–12

Kepler's laws and elliptical orbits

Drag the eccentricity and see an orbit stretch. Equal-time sectors with equal areas, the period law T² ∝ a³ and escape speed, with solved problems.

Grade 11–12

Newton’s law of gravitation, g and satellites

Play with two masses, the inverse-square graph, g above and below the Earth and a satellite orbit. Learn the law of gravitation, orbital speed, period and escape speed with solved problems.

Grade 11–12

Standing waves in strings and pipes

Pluck a string and blow across open and closed pipes in a simulation. See nodes, antinodes, harmonics, and learn how length, tension and temperature set the pitch, with solved problems.

Grade 11–12

Resonance tube and the speed of sound

Slide the water level in a resonance tube and find the loud spots yourself. See L1 = λ/4 − e and L2 = 3λ/4 − e, compute the speed of sound with v = 2f(L2 − L1), and practise solved problems.

Grade 11–12

Beats: when two close notes pulse

Add two waves of nearly equal frequency and watch the loudness pulse. See the envelope, read the beat frequency |f1 − f2|, hear the effect, and learn how guitarists tune by beats, with solved problems.

Grade 11–12

Doppler effect: moving sources, listeners and sonic booms

Drag a sound source faster and slower and watch the wavefronts bunch up ahead and stretch out behind. Learn the Doppler formula, moving listener, ambulance and train problems, and the sonic boom.

Grade 10–12

Prism, dispersion of light and the rainbow

Send white light through a prism, change the prism angle and incidence, and watch the spectrum form. Learn deviation, minimum deviation, dispersive power and how a raindrop makes a rainbow, with solved problems.

Grade 11–12

Kirchhoff’s laws: junction rule and loop rule

Build a two-loop circuit with two batteries and three resistors. Watch the currents split at a junction, see the voltage sums land on zero and learn how to solve Kirchhoff’s laws problems step by step.

Grade 12

Wheatstone bridge and metre bridge

Unbalance a Wheatstone bridge and watch the galvanometer needle swing. Find balance at P/Q = R/S, then slide the jockey on a metre bridge to measure an unknown resistance with solved examples.

Grade 11–12

Single-slit diffraction

Change the slit width and wavelength and watch light spread behind a single slit. See the intensity graph I = I₀(sin β/β)², the minima at a sin θ = mλ and the central maximum width 2λD/a, with solved problems.

Grade 10–12

Defects of the human eye and their correction

Switch between a normal, short-sighted, long-sighted and ageing eye. See why the image lands in front of or behind the retina, then fit the right lens and work out its power in dioptres.

Grade 12

Polarisation of light: Malus’s law and Brewster’s law

Rotate an analyser behind a polariser and watch I = I₀cos²θ on a graph, then bounce light off glass to find the Brewster angle. Includes polaroid sunglasses, three-filter puzzles and solved problems.

Grade 12

Charging and discharging a capacitor: the RC time constant

Charge and discharge a capacitor through a resistor. Change E, R and C, watch V = E(1 − e^(−t/RC)) and the current curve draw live, find the 63% time constant and the energy stored.

Grade 10–12

Magnetic field lines: bar magnet, current-carrying wire and solenoid

See magnetic field lines of a bar magnet, a straight current-carrying wire and a solenoid. Drag a compass, flip the current, and learn B = μ₀I/2πr, B = μ₀nI and the right-hand grip rule.

Grade 12

AC generator

Spin a coil between magnet poles and watch the sine wave of an AC generator build live. Change N, A, B and rpm, read E0 = NBAω and the rms value, and see why mains is 50 Hz.

Grade 10–12

Transformer

Change the primary and secondary turns of a transformer and watch the voltage step up or down. See Vs = Vp·Ns/Np, power conservation, real efficiency and why power lines use high voltage.

Grade 9–12

Heat transfer: conduction, convection and radiation

Heat a copper, aluminium, glass or wooden rod and watch Q/t = kAΔT/L, see convection currents circulate in a beaker, and see how radiated power grows as T⁴. With tables and solved problems.

Grade 12

Photoelectric effect: Einstein’s equation and the stopping potential

Shine light of any wavelength on sodium, zinc or copper in a vacuum tube. See why electrons leave only above the threshold frequency, how K = hf − φ sets the stopping potential, and why brightness changes only the current.

Grade 10–12

Motor effect: force on a current-carrying wire and the DC motor

Put a current-carrying wire in a magnetic field and watch it get pushed. Change B, I, L and the angle, test Fleming’s left-hand rule, then spin a DC motor with a split-ring commutator and see its torque graph.

Grade 11–12

Gas molecules and kinetic theory: pressure, temperature and speed

Watch gas molecules bounce around a box. Raise the temperature, change the gas, squeeze the volume, and see wall hits turn into pressure that matches PV = NkT. Compare speeds with the Maxwell–Boltzmann curve and calculate rms speed.

Grade 12

The semiconductor diode: p–n junction, I–V curve and rectifier

Bias a p–n junction and watch the depletion layer shrink or grow, carriers cross, and the Shockley I–V curve trace live. Compare silicon and germanium, see breakdown, then build a half-wave rectifier.

Grade 10–12

Radioactive decay: half-life, the decay law and penetration

Watch 240 nuclei decay at random, see the count follow N = N₀e^(−λt), measure the half-life from the graph, then test how alpha, beta and gamma radiation pass through paper, aluminium and lead.

Grade 11–12

The Bohr atom: orbits, energy levels and the hydrogen spectrum

Make a hydrogen electron jump between orbits n = 1 to 6, watch the photon colour come from 1/λ = R(1/n₁² − 1/n₂²), and see the Lyman, Balmer and Paschen series on an energy diagram and spectrum strip.