THE LESSON LIBRARY / PHYSICS
Physics, explored.
291 free learning pages. Pick a question and start exploring.
AC generator
Rotating the coil changes its projected area in the magnetic field. Faster rotation raises both output frequency and peak EMF. Maximum flux occurs when instantaneous EMF is zero.
Explore lesson PhysicssimulationAC peak and RMS
RMS is the DC-equivalent heating value for a resistor. It is not the mean voltage of a symmetric sinusoid, whose mean over a whole cycle is zero.
Explore lesson Physicsvirtual labAC sonometer resonance
Tune the bridge spacing while keeping tension and density fixed. Resonance occurs when the wire natural frequency matches the force frequency. An unbiased AC electromagnet…
Explore lesson PhysicssimulationAccelerate a rotating wheel
A constant net torque gives constant angular acceleration for a body with fixed inertia. The rotational equations mirror constant-acceleration linear motion, with torque…
Explore lesson PhysicssimulationAction and reaction
Each skater exerts a force on the other. The two forces are equal and opposite at the same instant, but act on different bodies. They therefore cannot cancel in the force…
Explore lesson PhysicssimulationAlign periodic signals
Period measures the time between repeats; frequency counts repeats per second. Phase shifts the signal along time without changing its period. Watch the current-point marker as…
Explore lesson PhysicssimulationAlpha beta gamma changes
Alpha is a helium nucleus, beta minus an electron from a nuclear conversion, and gamma a photon. Their charge and mass differ, producing different deflection and penetration…
Explore lesson PhysicschapterAlternating Current
7 free physics experiments and lesson notes for Alternating Current, with model limits, worked examples and Tamil explanations.
Explore lesson Physicsvirtual labAmmeter and voltmeter conversion
Choose the required range and derive the resistor to protect the sensitive coil. Check applied quantity against the chosen range before taking a reading; over-range values are…
Explore lesson PhysicssimulationAmpere wire and solenoid
Switch between a long wire and long solenoid. Ampere law yields an inverse-radius field around a wire and an approximately uniform interior field in a long solenoid.
Explore lesson PhysicssimulationApparent weight in a lift
A scale measures the normal support force. Upward acceleration requires N greater than mg; downward acceleration requires less. During free fall both lift and person accelerate…
Explore lesson PhysicschapterAtoms
5 free physics experiments and lesson notes for Atoms, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationAudit the direction of heat flow
Conservation of energy alone permits either direction of heat transfer. The second law selects the spontaneous direction by requiring nondecreasing total entropy. Heat flows from…
Explore lesson PhysicssimulationAverage & instantaneous
The secant joining two positions gives average velocity over that interval. The tangent at the current time gives instantaneous velocity. Speed is the magnitude of instantaneous…
Explore lesson PhysicssimulationBalance heat, work and internal energy
The first law is an energy balance. Heat entering increases internal energy; work done by the gas decreases it. Compression has negative work-by and can raise energy even without…
Explore lesson PhysicssimulationBalance three forces
Equilibrium requires the net force to vanish in every direction. Three large pulls can balance because their vector components cancel. Changing a magnitude or direction usually…
Explore lesson PhysicssimulationBands and thermal excitation
Allowed bands and gaps restrict electron states. A moderate gap permits thermally generated electron-hole pairs; a large gap suppresses them. A conductor needs available states…
Explore lesson PhysicssimulationBar magnet and equivalent solenoid
A bar magnet and a small current loop with the same dipole moment have the same far field. Field lines form closed loops; an isolated magnetic pole is absent from this model.
Explore lesson Physicsvirtual labBeam balance mass
Add known weights until the corrected pointer reaches zero. Equal arms compare masses directly; unequal arms need a lever-ratio correction.
Explore lesson Physicsvirtual labBernoulli flow apparatus
Narrowing a flowing tube raises speed and lowers pressure at equal height. Compare pressure-tube levels through the pressure-head readout; extreme invalid pressure predictions…
Explore lesson Physicsvirtual labBimetal-strip thermal bending
Bonded layers want to expand by different amounts. Their mismatch bends the strip. Reversing temperature change or swapping expansion coefficients reverses the bend direction.
Explore lesson PhysicssimulationBinding energy per nucleon
Intermediate nuclei have high binding per nucleon. Light nuclei can release energy by fusion and heavy nuclei by suitable fission when products have greater total binding. The…
Explore lesson PhysicssimulationBiot–Savart circular coil
Biot–Savart contributions from a circular coil add along its axis. Centre field grows with current and turn count and decreases with coil radius.
Explore lesson PhysicssimulationBohr hydrogen levels
Bohr states have discrete energies and angular momenta. Larger n means a larger radius, lower speed and energy closer to zero. A bound state has negative energy relative to a…
Explore lesson Physicsvirtual labBoyle-law gas syringe
Compress a sealed syringe slowly while holding temperature fixed. Its absolute pressure rises as volume falls; the PV product remains constant.
Explore lesson PhysicssimulationBraking and kinetic energy
The work-energy theorem connects net work to the change in kinetic energy. A brake does negative work because its force opposes displacement. The stopping distance is initial…
Explore lesson PhysicssimulationBring two blocks into contact
Temperature describes thermal state; heat is energy transferred because temperatures differ. The isolated blocks approach a common temperature determined by their heat…
Explore lesson Physicsvirtual labBulb branches and fuse model
Each branch switch controls its own parallel bulb, while the common fuse controls both. Current demand is the sum of branch currents. Changing voltage changes power through the…
Explore lesson PhysicssimulationCan the ladder stay balanced?
Taking moments about the foot determines the horizontal wall reaction. The floor must provide equal horizontal friction and support the weight. A steeper ladder needs less…
Explore lesson PhysicssimulationCapacitor energy
Energy resides in the electric field. A battery-connected dielectric insertion increases stored energy; inserting dielectric into an isolated capacitor decreases it.
Explore lesson Physicsvirtual labCapillary rise with detergent
Read the meniscus height above the reservoir. A smaller bore produces greater rise. The detergent selector demonstrates reduced tension using an explicit calibration factor.
Explore lesson Physicsvirtual labCell EMF and internal factors
Read open-circuit voltage first, then close the load switch and observe terminal drop. Vary electrode spacing or immersed area to change internal resistance while holding the…
Explore lesson PhysicssimulationChange a mass and spring
A stretched spring pulls the mass toward equilibrium; a compressed spring pushes it back. The restoring force produces SHM. Mass and stiffness determine period, while amplitude…
Explore lesson PhysicssimulationChange molecular collision density
Mean free path is the average travel distance between molecular collisions. Higher number density or larger collision diameter makes collisions more frequent. Avogadro number…
Explore lesson PhysicssimulationChange molecular mass and temperature
An equilibrium gas has a distribution of speeds. RMS speed comes from the mean squared speed and exceeds the mean speed, which in turn exceeds the most probable speed. Lighter…
Explore lesson PhysicssimulationChange the speed of sound in a gas
Sound propagation depends on a gas’s adiabatic compressibility and density. In an ideal gas their pressure dependence cancels, leaving temperature, molar mass and heat-capacity…
Explore lesson PhysicssimulationChange tube radius and wetting
Surface tension around the tube balances the weight of the raised liquid column. Smaller radius produces a larger rise. A contact angle above 90° reverses the sign, producing…
Explore lesson PhysicssimulationCharge and dipole potential energy
Choose a point-charge pair or a dipole in an external field. Pair energy kq₁q₂/r can be positive or negative. Dipole energy −pE cosθ is lowest when aligned with the field.
Explore lesson PhysicssimulationCharge transfer and conservation
Two identical conducting spheres share charge when joined. Move the equalisation fraction from separated to fully connected and check the conserved total.
Explore lesson PhysicssimulationCoherence and visibility
A stable phase relation preserves interference over time. Random relative phase washes out the cross term in the averaged intensity. Even perfectly coherent unequal sources do…
Explore lesson Physicsvirtual labCoil inductance geometry
Vary one geometric factor at a time. Turns enter quadratically; area and permeability linearly; length inversely. The negative induced emf expresses opposition to an increasing…
Explore lesson Physicsvirtual labCollect an image on a screen
Change object location and move the screen to the real image. Lens and mirror send the outgoing light to opposite bench sides, even though their positive-distance equations share…
Explore lesson PhysicssimulationCollisions in 1D and 2D
An isolated collision conserves vector momentum. Restitution specifies how relative normal velocity changes; e = 1 is elastic and e = 0 removes relative normal motion. For smooth…
Explore lesson PhysicssimulationCombine nearby frequencies
Nearby tones alternate between constructive and destructive interference. The loudness envelope repeats at the difference frequency. The signed envelope has twice the…
Explore lesson Physicsvirtual labCombined-lens focal measurement
Compare contact and separated holders. Touching lenses add power; a gap changes the system power and principal-plane location. Equal positive and negative contact powers make an…
Explore lesson PhysicssimulationCompare a drop and soap bubble
Surface tension makes the interior pressure exceed the exterior pressure. Smaller spheres need a larger pressure difference. A thin soap bubble has two interfaces and twice the…
Explore lesson PhysicssimulationCompare absorption and emission
A surface that absorbs strongly also emits strongly under matching conditions. In an enclosure of the same temperature, absorbed and emitted power balance for every absorptivity.…
Explore lesson PhysicssimulationCompare fast and slow gas compression
A gas compressed without cooling becomes hotter and resists more strongly than a gas allowed to remain isothermal. Consequently its adiabatic bulk modulus is γ times its…
Explore lesson PhysicssimulationCompare isothermal and adiabatic paths
An isothermal gas exchanges heat to keep its temperature fixed as it expands. A reversibly adiabatic gas receives no heat, so expansion work lowers its internal energy and…
Explore lesson PhysicssimulationCompare loaded wires
A long thin wire stretches more than a short thick wire under the same load. Modulus describes the material; the wire stiffness also depends on its dimensions.
Explore lesson PhysicssimulationCompare monatomic and diatomic gases
At constant pressure some heat supplies expansion work, so Cp exceeds Cv by R per mole. More active modes raise both capacities and bring their ratio closer to one.
Explore lesson PhysicssimulationCompare open and closed air columns
An open end allows air displacement while a closed end constrains it. Two open ends support every integer harmonic; one closed end supports only odd harmonics. The mode index…
Explore lesson PhysicssimulationCompare shapes around an axis
Moment of inertia depends on how mass is distributed relative to an axis. More mass farther from the axis increases I. Radius of gyration is the single effective radius that…
Explore lesson PhysicssimulationCompare three thermal states
The zeroth law makes temperature a consistent comparison: two bodies that separately equilibrate with the same thermometer are at the same temperature as each other. Set both…
Explore lesson PhysicssimulationCompare transverse and longitudinal motion
A wave carries a disturbance through a medium. In a transverse wave particles move perpendicular to propagation; in a longitudinal wave they move parallel to it. Follow the…
Explore lesson PhysicssimulationCompound optical power
Lens powers add in contact. Separation introduces an extra term and shifts the principal planes. A plane mirror immediately at a thin lens sends light through that same power…
Explore lesson PhysicssimulationCompress an ideal gas isothermally
Pressure rises as an isothermal gas is compressed. The work is the area under its inverse-volume pressure curve, giving a logarithm rather than simply multiplying one pressure by…
Explore lesson PhysicssimulationCompress and shear a material
Bulk modulus describes resistance to volume change under uniform pressure. Shear modulus describes resistance to shape change under tangential stress. A negative volume strain…
Explore lesson Physicsvirtual labConcave lens in a converging beam
A concave lens can yield a real final image when its incident beam is already converging sufficiently. The virtual-object distance must be signed, otherwise the focal calculation…
Explore lesson Physicsvirtual labConcave-mirror u-v bench
Move the screen until its distance agrees with the calculated real-image position. Record object and image distances, then estimate focal length. An object inside focus yields no…
Explore lesson PhysicssimulationConduct heat through two layers
Thermal resistances in series add. The poorly conducting or thicker layer takes the larger temperature drop. In a steady state the same heat rate passes through both layers.
Explore lesson PhysicssimulationConstant acceleration
Acceleration is the rate of change of velocity. When velocity and acceleration have opposite signs, speed decreases until velocity reaches zero. Continued acceleration then…
Explore lesson PhysicssimulationControl a traveling harmonic wave
The traveling-wave phase advances along the medium as time passes. Frequency sets the oscillation rate and wavelength sets the spatial repetition. Together they determine the…
Explore lesson Physicsvirtual labConvex mirror with converging lens
Use a convex lens to create a converging beam aimed at a point behind the convex mirror. Adjust mirror position until that point matches its centre of curvature. Normal incidence…
Explore lesson Physicsvirtual labConvex-lens reciprocal plot
Obtain different sharp u-v pairs by moving the object and screen. Their reciprocals lie on a line. Reading the intercept provides another focal-length estimate.
Explore lesson Physicsvirtual labCooling-curve thermometer
Take temperature readings at equal time intervals and observe a decreasing slope as the body approaches room temperature. Correct a thermometer zero offset before fitting.
Explore lesson Physicsvirtual labCore-dependent coil impedance
Compare current with and without the core at the same RMS voltage and frequency. The core raises inductance in this linear guide, increasing reactance and reducing current.…
Explore lesson PhysicssimulationCoulomb force
Change signs to switch attraction and repulsion. Increase separation to see the force decrease with the square of distance. Positive force here means repulsion.
Explore lesson PhysicschapterCurrent Electricity
9 free physics experiments and lesson notes for Current Electricity, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationCurrent-loop torque and moment
The magnetic moment points along the loop normal by the right-hand rule. A uniform magnetic field creates torque even though net translational force on the closed loop is zero.
Explore lesson PhysicssimulationCurved boundary refraction
Curvature and an index difference give an interface optical power. The focal object distance differs from the focal image distance because the two media have different indices.
Explore lesson Physicssimulationde Broglie wavelength
Matter wavelength is set by momentum. Equal accelerating voltage gives equal kinetic energy to electron and proton, but their different masses produce different momenta and…
Explore lesson PhysicssimulationDecay populations and half-life
Half-life is a population statistic. After each half-life the expected remaining count halves, while any small sample may fluctuate. Mean lifetime is longer than half-life and…
Explore lesson PhysicssimulationDia, para and ferromagnetism
Diamagnetic susceptibility is weak and negative; paramagnetic susceptibility is weak and positive. Ferromagnetism can be much stronger and nonlinear; this lesson uses an…
Explore lesson PhysicssimulationDielectric polarization
Polarization slightly separates positive and negative bound charge. Compare a battery-connected capacitor, which holds voltage, with an isolated capacitor, which holds free charge.
Explore lesson PhysicssimulationDimensional applications
Assume a pendulum period depends only on length l and gravity g through T = C lᵃ gᵇ. Matching time dimensions gives a = 1/2 and b = −1/2. It cannot determine C. The ideal…
Explore lesson PhysicssimulationDimensional balance
Every physical equation must have matching dimensions on both sides. Force has dimensions M L T⁻². Multiplying mass by acceleration produces the same dimensions; multiplying mass…
Explore lesson Physicsvirtual labDiode and LED meter check
Use both lead orientations and compare silicon with an LED. A valid forward drop and reverse open indication are expected. An insufficient-compliance meter can show OL even for a…
Explore lesson PhysicssimulationDisplacement current
A charging capacitor carries conduction current in its wires and equal displacement current through its gap. No charge carriers need cross the dielectric gap.
Explore lesson PhysicssimulationDistance & displacement
Position states where the walker is relative to an origin. Displacement is final position minus starting position. Distance adds the lengths of all travelled parts. Reversing…
Explore lesson PhysicssimulationDistribute energy across active modes
Equipartition assigns equal average energy to each active quadratic degree of freedom. Adding active rotational or vibrational terms raises total energy and heat capacity at the…
Explore lesson PhysicssimulationDot & cross products
The dot product is a scalar measuring alignment: positive for acute angles, zero at 90°, negative for obtuse angles. The cross product is a vector perpendicular to both inputs.…
Explore lesson Physicsvirtual labDouble-incline energy transfer
Release a cart from rest on one slope and measure the rise on the second. Without losses it regains its original height irrespective of slope; friction lowers the return height.
Explore lesson PhysicssimulationDrain a tank and compare lift pressure
A liquid head becomes jet kinetic energy, giving an exit speed proportional to the square root of head. In the separate air example, faster flow above than below gives lower…
Explore lesson PhysicssimulationDrift velocity and mobility
A small average drift speed can produce appreciable current because a metal contains many mobile electrons. Electron drift is opposite to conventional current.
Explore lesson PhysicssimulationDrive an oscillator near resonance
A periodic force drives a damped oscillator most strongly near its resonance. Damping broadens and lowers the response peak. The settled motion lags behind the driving force…
Explore lesson PhysicssimulationDrop a sphere through viscous liquid
Weight, buoyancy and viscous drag determine a falling sphere’s speed. As speed grows, drag grows until the net force vanishes and the sphere reaches terminal speed. Viscosity…
Explore lesson PhysicssimulationDry or lubricated
A lubricant can reduce direct contact between rough surfaces and change their friction. Here you choose lower coefficients and compare identical blocks. A weaker push may move…
Explore lesson PhysicschapterDual Nature of Radiation & Matter
4 free physics experiments and lesson notes for Dual Nature of Radiation & Matter, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationEddy-current magnetic braking
A moving conductor develops eddy currents that resist motion. This effective-loop model shows increased braking with stronger field and smaller loop resistance.
Explore lesson PhysicschapterElectric Charges & Fields
7 free physics experiments and lesson notes for Electric Charges & Fields, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationElectric dipole field and torque
Compare axial and equatorial fields and rotate a dipole in a uniform external field. The field falls as r⁻³ in the far-field approximation.
Explore lesson PhysicssimulationElectric flux and Gauss law
Tilt an open surface to change its projected area. Closed-surface flux instead depends on net enclosed charge; external charges contribute zero net closed flux.
Explore lesson PhysicssimulationElectrical power and Joule heating
The circuit converts electrical energy into heat. With fixed resistance, doubling voltage doubles current and quadruples power.
Explore lesson PhysicschapterElectromagnetic Induction
5 free physics experiments and lesson notes for Electromagnetic Induction, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationElectromagnetic spectrum
Move continuously from radio to gamma rays. Frequency increases as wavelength decreases; photon energy rises with frequency. Spectrum boundaries are conventional and overlap…
Explore lesson PhysicschapterElectromagnetic Waves
3 free physics experiments and lesson notes for Electromagnetic Waves, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationEMF and terminal voltage
EMF is energy supplied per unit charge inside the source. Internal resistance causes terminal voltage to drop when a load draws current.
Explore lesson PhysicssimulationEqual work, different power
Work is energy transferred. Power is the rate of that transfer. Both lifts raise the same mass through the same height and therefore do equal work against gravity. The lift with…
Explore lesson PhysicssimulationEquipotential surfaces
All points at one radius from a point charge have the same potential. Move between spherical surfaces to change potential; travel along one surface requires zero electrostatic…
Explore lesson PhysicssimulationExplore an ideal-gas state
Pressure, volume, temperature and gas amount are related by the equation of state. At fixed amount and temperature, doubling volume halves pressure. Internal energy of this ideal…
Explore lesson PhysicssimulationExplore the gravitational energy well
Gravitational potential is potential energy per unit probe mass. With zero at infinity it is negative at finite distance; work must be supplied to move the probe outward. Field…
Explore lesson PhysicssimulationExplore water near 4°C
Water contracts when warmed from 0°C to about 4°C and expands when warmed further. Its density maximum explains why lakes can retain denser liquid below a colder surface.
Explore lesson Physicsvirtual labFalling-sphere viscosity
Time a sphere only after it has reached terminal speed. Stokes law applies when Reynolds number is much smaller than one; the readout explicitly flags choices outside that regime.
Explore lesson PhysicssimulationFaraday flux and induced EMF
Hold coil geometry fixed and vary the rate of field change. A large but steady field gives zero EMF; changing field creates an induced voltage.
Explore lesson Physicsvirtual labFind a virtual circuit fault
Distinguish an open lead from a reversed source and a bypassed load. Correcting the selected fault restores the expected current. A negative meter reading can indicate reversed…
Explore lesson PhysicssimulationFind the balance point
The centre of mass weights each position by its mass. A uniform rod contributes its own midpoint. Move either particle or change its mass to move the balance point toward the…
Explore lesson PhysicssimulationFind the pipe-flow transition
Reynolds number compares inertia with viscous effects. A larger speed or diameter promotes transition, while higher viscosity favours laminar flow. The threshold is approximate…
Explore lesson PhysicssimulationFission and fusion energy balance
Nucleon number and charge balance before comparing masses. A positive Q is released energy for the specified products. Fusion and fission are different rearrangements but obey…
Explore lesson PhysicssimulationFollow a collision centre
Internal collision forces change the carts individually, while their centre of mass continues along a straight line at a constant velocity. The sticking collision dissipates…
Explore lesson Physicsvirtual labForward and reverse diode meters
Reverse the virtual polarity and compare the voltage and current ranges. The resistor limits forward current. A reverse microamp reading is much smaller than the forward…
Explore lesson PhysicssimulationFree charge in conductors and insulators
Free charges redistribute in an electrostatic conductor until the interior field vanishes. A fixed uniform charge density in an insulating sphere instead gives an interior field…
Explore lesson PhysicssimulationGalvanometer and meter conversion
A radial field makes coil torque proportional to current. Add a small parallel shunt for an ammeter or a large series resistor for a voltmeter. Values beyond 90° indicate…
Explore lesson Physicsvirtual labGalvanometer half deflection
Adjust a shunt until deflection is half the unshunted reading. Then use the finite series-resistance correction to infer coil resistance and use original current per division for…
Explore lesson PhysicssimulationGaussian wire, sheet and shell
Switch the charge geometry. A wire gives a 1/r field, an ideal sheet gives a distance-independent field, and a shell gives zero interior field.
Explore lesson PhysicssimulationGlass slab refraction
The ray bends toward the normal on entering glass and away on leaving. The parallel faces restore its original direction but shift its line sideways. Thickness changes shift…
Explore lesson Physicsvirtual labGlass-slab pin and shift reading
The two outside pin lines should be parallel. Measure their shortest separation, not their horizontal coordinate difference. Compare this shift with Snell’s law and correct an…
Explore lesson Physicsvirtual labGraph scales and error bounds
Select graph scale through the measured range, correct a systematic zero shift and compare resolution bounds with inferred slope. The plotted staircase shows finite instrument…
Explore lesson PhysicschapterGravitation
7 free physics experiments and lesson notes for Gravitation, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationHalf and full-wave rectification
A half-wave circuit passes one polarity. A bridge reverses the negative half-cycle through the load, producing same-polarity pulses at twice the input frequency. Rectified output…
Explore lesson PhysicssimulationHead-to-tail vectors
Move the tail of the second arrow to the head of the first. The resultant joins the original tail to the final head. Subtracting B means adding −B. A negative scale factor…
Explore lesson PhysicssimulationHeat a solid, liquid and ideal gas
Heating expands most materials, but coefficients and constraints matter. A solid’s volume coefficient is roughly three times its linear coefficient; a liquid has its own volume…
Explore lesson PhysicssimulationHeat ice through state changes
During melting or boiling, heat changes the state while temperature stays constant. Between state changes, heat increases temperature according to the relevant specific heat. The…
Explore lesson Physicsvirtual labHeat-loss surface factors
Compare surface area, airflow represented by h and emissivity. Radiation uses absolute Kelvin temperature, while convection uses temperature difference. This apparatus study…
Explore lesson Physicsvirtual labHollow-prism liquid comparison
Use the same prism angle for two fluids and retune incidence for each minimum. The larger-index liquid produces a larger minimum deviation. Prism walls must be accounted for in a…
Explore lesson PhysicssimulationHuygens wavefront refraction
Every point on a wavefront acts as a source of secondary wavelets. A slower wave advances less far during the same time, tilting the new wavefront. The frequency remains fixed at…
Explore lesson PhysicssimulationHydrogen spectral transitions
A spectral line records the energy difference between levels, not the energy of either level alone. Downward transitions emit photons; upward transitions absorb matching photons.…
Explore lesson PhysicssimulationHydrogen-like ions
A stronger nuclear charge attracts the same single electron more tightly. At fixed n, radius decreases as1/Z and binding energy magnitude increases as Z². Hydrogen-like means one…
Explore lesson Physicsvirtual labIdentify components and marking codes
Inspect the specimen shape and decode its markings. Resistor bands and capacitor digits encode values in different units. A diode stripe identifies a terminal rather than a…
Explore lesson PhysicssimulationIdentify string nodes and harmonics
Two opposite traveling waves form a standing pattern with fixed nodes. Both fixed ends must be nodes, so only wavelengths 2L/n fit. Higher tension raises all harmonic…
Explore lesson PhysicssimulationImpulse and contact time
Momentum is mv. Newton’s second law links force to its rate of change; integrating force over time gives impulse. Both the short and long triangular force pulses remove the same…
Explore lesson Physicsvirtual labIncline spring-balance reading
A spring balance holds a block at rest on a frictionless incline. Plot holding force against sine of the incline angle to obtain a straight line of slope mg.
Explore lesson PhysicssimulationIndependent x & y motion
Uniform motion in a plane has constant horizontal and vertical velocity components. Each coordinate evolves as a separate straight-line equation, but both use the same elapsed…
Explore lesson PhysicssimulationInertia trolleys
Mass measures resistance to a change in velocity. A net force accelerates a trolley; the same force produces less acceleration on a larger mass. Remove the push and both continue…
Explore lesson PhysicssimulationIntrinsic and doped carriers
Donors favor electrons and acceptors favor holes. Minority carriers remain present. At equilibrium the carrier product equals ni² in this nondegenerate model, and ionized dopants…
Explore lesson Physicsvirtual labIrregular solid displacement volume
Use a graduated cylinder to measure a fully submerged irregular solid or lamina. The difference removes a common additive zero error; two rounded readings still contribute…
Explore lesson PhysicssimulationJunction bias and diode IV
Forward bias lowers the junction barrier and narrows depletion; reverse bias widens depletion and usually permits only small leakage before breakdown. The threshold drawing is a…
Explore lesson PhysicssimulationKeep a vertical loop taut
Energy determines how speed changes while the bob climbs. Tension also must remain non-negative because a string cannot push. At the top the minimum taut speed is √(gr), which…
Explore lesson PhysicschapterKinetic Theory
6 free physics experiments and lesson notes for Kinetic Theory, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationKirchhoff junction and loop rules
One series resistor feeds two parallel branches. Changing one branch changes the node voltage and both branch currents. The readout verifies charge conservation at the junction.
Explore lesson PhysicschapterLaws of Motion
9 free physics experiments and lesson notes for Laws of Motion, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationLCR response to DC and AC
Compare AC steady-state frequency response with switched DC subcircuits. The DC selector explicitly chooses RC, LR or ideal LC; it is not a full damped second-order LCR transient…
Explore lesson Physicsvirtual labLDR lamp distance readings
Change distance while holding lamp output fixed. Illuminance falls with distance squared, while the resistance response is nonlinear. Read resistance rather than treating it as a…
Explore lesson Physicsvirtual labLDR response to lamp power
Keep distance fixed while varying lamp power. The calibration converts lamp watts into illuminance at the sensor; the LDR converts illumination into nonlinear resistance. Compare…
Explore lesson PhysicssimulationLED photodiode and solar cell
An LED converts forward electrical power to photons. A photodiode converts light to measurable current, commonly under reverse bias. A solar cell can deliver power to a load…
Explore lesson PhysicssimulationLens shape and optical power
Lens power comes from index contrast and both surface curvatures. Increasing curvature or index increases focusing power. Dioptres use focal length in metres.
Explore lesson PhysicssimulationLenz law direction
The minus sign means the induced current creates a field opposing the change in flux. When increasing flux becomes decreasing flux, induced current reverses. Heating remains…
Explore lesson PhysicssimulationLevel and banked roads
A vehicle needs inward net force mv²/r. On a level road static friction supplies it. On a banked road the tilted normal contributes. At the design speed no friction is needed…
Explore lesson PhysicssimulationLink a pair of pistons
A pressure increase applied to a confined fluid reaches both pistons. The larger piston produces more force, but moves a smaller distance so the ideal lift conserves work.
Explore lesson PhysicssimulationLink wall impacts to pressure
Molecules transfer momentum when they bounce from a wall. Random isotropic motion makes the pressure depend on the mean squared speed. Temperature measures their average…
Explore lesson Physicsvirtual labLiquid expansion capillary
Warm a liquid-filled vessel with a narrow capillary. The observed rise reflects liquid expansion minus vessel expansion, so apparent expansion is smaller than true expansion.
Explore lesson Physicsvirtual labLiquid lens with plane mirror
Find the no-parallax needle distance in air and with the liquid layer. The liquid layer has negative power in this geometry. The focal change and known curvature give the liquid…
Explore lesson Physicsvirtual labLoaded metre-scale depression
Place a metre scale on two supports and add load at its midpoint. Depression grows with span cubed and decreases with thickness cubed; use modest loads within elastic bending.
Explore lesson PhysicssimulationLogic gates and truth tables
A truth table defines output for every input combination. Inverting gates reverse a basic logical operation. Checking every row avoids confusing OR with AND or NAND with NOR.
Explore lesson PhysicssimulationLorentz force and circular motion
Only velocity perpendicular to B contributes to magnetic force. Parallel velocity gives no magnetic force. The magnetic-only circular radius is shown separately from the chosen…
Explore lesson PhysicssimulationLower a pressure probe
A deeper probe supports a larger liquid column and reads greater pressure. Density determines the slope. Container shape does not affect pressure at a given depth in the same…
Explore lesson PhysicssimulationMagnetic dipole fields and torque
Axial field magnitude is twice the equatorial magnitude at equal radius. A separate uniform external field rotates the magnet toward its minimum-energy alignment.
Explore lesson PhysicschapterMagnetism & Matter
4 free physics experiments and lesson notes for Magnetism & Matter, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationMagnetization and temperature
Higher temperature disrupts alignment. Paramagnetic χ follows a Curie law here; the illustrative ferromagnetic response loses its strong ordering above the chosen Curie…
Explore lesson PhysicssimulationMass defect and binding
A bound system has less mass than its separated constituents. The mass difference corresponds to the energy needed to separate the nucleus. Atomic and nuclear mass conventions…
Explore lesson PhysicssimulationMatch a sidereal rotation
A geostationary satellite remains above one equatorial longitude only when its orbit is circular, equatorial, prograde and has the Earth’s sidereal rotation period. Changing the…
Explore lesson PhysicschapterMechanical Properties of Fluids
10 free physics experiments and lesson notes for Mechanical Properties of Fluids, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicschapterMechanical Properties of Solids
5 free physics experiments and lesson notes for Mechanical Properties of Solids, with model limits, worked examples and Tamil explanations.
Explore lesson Physicsvirtual labMetre bridge combinations
Slide the jockey until detector voltage reaches zero. Repeat with one resistor and its series or parallel combination; do not infer resistance from an unbalanced position.
Explore lesson Physicsvirtual labMetre-scale moments
Support a metre scale at its own centre of mass so its weight creates no moment. Adjust suspended masses or pivot distances to balance clockwise and anticlockwise moments.
Explore lesson PhysicssimulationMicroscope and telescope
An objective and an eyepiece perform different jobs. The telescope compares angular sizes of distant objects. A microscope uses a real intermediate image before the eyepiece…
Explore lesson PhysicssimulationMix hot and cold materials
A calorimeter balances heat lost against heat gained. A larger hot heat capacity pulls the final temperature toward the hot initial value. Specific heat has units J/(kg·K), while…
Explore lesson PhysicssimulationMomentum after release
The spring pushes both carts internally. With no external impulse, total momentum remains its initial value, even while spring energy becomes kinetic energy. From rest, momenta…
Explore lesson PhysicschapterMotion in a Plane
7 free physics experiments and lesson notes for Motion in a Plane, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicschapterMotion in a Straight Line
7 free physics experiments and lesson notes for Motion in a Straight Line, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationMove a source and an observer
An approaching source compresses the wavefront spacing and raises observed frequency. An approaching observer meets wavefronts faster. Their velocities enter different parts of…
Explore lesson PhysicssimulationMove the force lever
Torque measures the turning effect of a force. Only its component perpendicular to the lever turns the body. A force along the lever produces zero torque even when its magnitude…
Explore lesson PhysicschapterMoving Charges & Magnetism
7 free physics experiments and lesson notes for Moving Charges & Magnetism, with model limits, worked examples and Tamil explanations.
Explore lesson Physicsvirtual labMultimeter setup and reading
Meter function and connection must agree. Across-component voltage and series current are different measurements. Test continuity only in the source-off state, then compare a low…
Explore lesson PhysicssimulationNarrow a flowing pipe
Continuity speeds up liquid where a pipe narrows. Bernoulli links this kinetic-energy increase and any height increase to a pressure decrease. The outlet area control changes…
Explore lesson PhysicssimulationNuclear size and composition
Protons define an element; neutrons distinguish its isotopes. Nuclear radius grows with the cube root of nucleon number, making average nuclear density approximately constant.…
Explore lesson PhysicschapterNuclei
6 free physics experiments and lesson notes for Nuclei, with model limits, worked examples and Tamil explanations.
Explore lesson PhysicssimulationOersted current and compass
A current produces magnetic field circles around a straight wire. Reversing current reverses circulation and compass deflection; the right-hand rule gives direction.
Explore lesson PhysicssimulationOhmic and non-linear VI curves
An ohmic element has a constant V/I ratio at fixed temperature. The illustrative filament model increases resistance with heating and bends the VI curve.
Explore lesson Physicsvirtual labOptical needle-parallax focus
Move the viewpoint sideways, then adjust the image needle until relative motion vanishes. Coincidence identifies image distance without requiring a screen. A stationary view…
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