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A STUDENT’S STARTING GUIDE

Free NEET & IIT-JEE
science simulations.

Explore Physics and Chemistry concepts for NEET and IIT-JEE study, alongside Biology and human anatomy for NEET learning. Start with one question, change one variable and explain what you observe.

These activities are concept experiments and virtual labs. This guide does not provide a timed NEET or JEE mock-test interface.

A FEW GOOD PLACES TO BEGIN

Choose a concept.
Follow the evidence.

Every linked activity is free.
No student account is required.

The Physics collection contains 260 experiments: 195 concept experiments and 65 practical labs. Chemistry also includes 4,500 numbered reading pages; those notes are separate from its interactive simulations.

A place in this guide is not a claim of complete exam coverage. Match a topic to your current textbook and syllabus, and read the assumptions on the individual activity.

PHYSICS / START HERE

Predict a change. Compare the motion.

Begin with a Class 11 or Class 12 concept, or investigate how a practical measurement works.

PhysicsClass 11 · Motion in a plane

Projectile trajectory

Change: Keep the launch speed fixed and change the launch angle. Predict the path before restarting the flight.

Observe: Compare horizontal and vertical velocity at the highest point. The vertical component becomes zero; the horizontal component usually does not.

Model limits: Constant gravity and no air resistance. The familiar range formula assumes the launch and landing heights are equal.

Explain: Does zero vertical velocity at the top mean the acceleration is zero?

Page text: English + தமிழ். Study audience: NEET + IIT-JEE.

Open activity

Read this activity’s explanation and limits

PhysicsClass 12 · Wave optics

Young double-slit fringes

Change: Increase the wavelength, then reset and increase the slit separation. Change one quantity at a time.

Observe: Longer wavelength spreads the fringes; wider slit separation brings them closer together. Connect the pattern to β = λD/d.

Model limits: Equal coherent narrow slits and small angles; this model leaves out the diffraction envelope to isolate interference spacing.

Explain: Which two changes could keep the fringe spacing unchanged?

Page text: English + தமிழ். Study audience: NEET + IIT-JEE.

Open activity

Read this activity’s explanation and limits

PhysicsPractical measurement · Oscillations

Pendulum length and stopwatch

Change: Compare two lengths, then change the bob mass. Time several full oscillations and divide by their number.

Observe: Length changes the period; bob mass does not change the ideal period. Compare a single timed cycle with a longer timing interval.

Model limits: A small-amplitude model with a first amplitude correction. The stopwatch rounds readings; use the length to the bob’s centre.

Explain: Why does timing several cycles help when the stopwatch has limited resolution?

Page text: English + தமிழ்.

Open activity

Read this activity’s explanation and limits

CHEMISTRY / START HERE

Build the picture behind the formula.

Explore atomic structure and bond formation before returning to your chapter notes.

ChemistryAtomic structure · Build an atom

Bohr atom builder

Change: Keep the proton count fixed. Change neutrons, then change electrons. Read the name, mass number and charge.

Observe: Protons determine the element. Changing neutrons makes isotopes; changing electrons makes ions.

Model limits: Bohr shells are a teaching picture. Electrons do not travel around an atom on the circular paths shown.

Explain: Build a chloride ion, Cl⁻. Which particle count explains its negative charge?

Page text: English.

Open activity

Read this activity’s explanation and limits

ChemistryChemical bonding · Hydrogen molecule

Covalent orbital overlap

Change: Open Bond formation (H₂) and move the internuclear-distance slider from far apart towards the energy minimum.

Observe: Compare orbital overlap with the energy curve. Move closer than the minimum and notice the steep rise in energy.

Model limits: This investigation illustrates covalent bonding in H₂. Its single energy curve is not a calculation for every molecule.

Explain: Why is bringing the nuclei as close as possible not the lowest-energy arrangement?

Page text: English.

Open activity

Read this activity’s explanation and limits

BIOLOGY / START HERE

Trace the process. Inspect the structure.

Connect a teaching model to the Biology chapter, then use anatomy to strengthen your spatial understanding.

BiologyPlant physiology · Limiting factors

Limiting factors — Biology Lab

Change: Hold CO₂ low and raise the light input. Then raise CO₂ and compare the result with your prediction.

Observe: Increasing a factor that is not currently limiting may leave the displayed rate unchanged.

Model limits: The relative teaching rate is min(light, CO₂). Water and temperature are held suitable; this is not a measured plant-response curve.

Explain: When would extra light fail to raise the model rate?

Page text: English + தமிழ்.

Open activity

Read the related Class 11 chapter: Photosynthesis in Higher Plants

BiologyHuman physiology · Urine formation

Urine formation — Biology Lab

Change: Step through filtration, reabsorption and secretion. Then change the ADH signal and compare water-conservation tendencies.

Observe: Track the direction of movement between blood and the nephron. Distinguish filtration from the later regulation of water reabsorption.

Model limits: The ADH control is qualitative and does not predict urine volume. Other conditions are held constant; ADH does not directly control glomerular filtration.

Explain: Why should a higher ADH setting not be interpreted as a direct change to filtration?

Page text: English + தமிழ்.

Open activity

Read the related Class 11 chapter: Excretory Products and Their Elimination

Biology3D anatomy · Structure before process

Heart — 3D anatomy

Change: Open the heart in the atlas. Rotate the model and use the available selection or isolation controls to inspect its position.

Observe: Relate the heart to the lungs and diaphragm, then connect the structure to the chapter on the pulmonary and systemic circuits.

Model limits: An anatomy model shows structures and their relationships. It is not a patient-specific model of blood flow or a diagnostic tool.

Explain: Can you explain the two circuits using the chapter, without treating the 3D shape as a working circulation simulation?

Page text: English.

Open activity

Read this activity’s explanation and limits

Read the related Class 11 chapter: Body Fluids and Circulation

MAKE THE EXPERIMENT COUNT

Predict. Change.
Explain.

  1. Predict first. Write one sentence about what should happen. Name the quantity you will change and what you will keep fixed.
  2. Change one input. Compare two settings. Read the graph, number or structure rather than relying only on the animation.
  3. Explain the difference. Connect the result to a formula or biological mechanism. If your prediction was wrong, state which assumption you need to change.
  4. Return to a question. Try a textbook or practice question on the same concept. State where the simulation’s assumptions apply and where they stop applying.

To follow your course, browse Class 11 experiments, Class 12 experiments, Physics resources tagged for NEET study or Physics resources tagged for IIT-JEE study. More chapter explanations are available in the Physics topic directory and Chemistry note directory.

LEARN IN A LANGUAGE YOU CONNECT WITH

English and Tamil.
Check each activity.

Language availability is shown on the cards above. The selected Physics pages and Biology labs include English and Tamil text; the two selected Chemistry guides and the heart explanation are in English. A language label on the guide page does not promise that every control inside its linked app is translated.

The numbered Chemistry collection currently has Tamil translations for What Is Chemistry? and What Is Matter?. Use the Tamil-available resources filter for other confirmed resources.

முதலில் ஒரு கருத்தைத் தேர்ந்தெடுங்கள். என்ன நடக்கும் என்று முன்கணித்துப் பின் ஒரு அளவை மட்டும் மாற்றுங்கள். கிடைக்கும் முடிவைப் பாடக் கருத்துடன் இணைத்து விளக்குங்கள். ஒவ்வொரு செயல்பாட்டிலும் தமிழ் வசதியும் மாதிரியின் வரம்புகளும் மாறலாம்; அந்தப் பக்கத்தில் உள்ள விளக்கத்தைப் படித்துத் தொடங்குங்கள்.

Some interactive models need JavaScript and WebGL. If a 3D view does not load, start with its linked explanation. See the resource credits and sources for attribution and the Kalviyogi profile for the purpose behind the collection.