Physics · Class 12

Photons build an interference pattern

Each photon creates a localized detection while many detections reveal an interference probability pattern. Wavelength determines the energy and momentum of each photon, not whether the detector records a localized event.

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Photons build an interference pattern

ஒவ்வொரு ஃபோட்டானும் தனித்த புள்ளியாகப் பதிவாகும். பல பதிவுகள் சேரும்போது குறுக்கீட்டு வடிவம் தெரியும்.

Key notes, relationships and model limits

Key relationship

E=hν=hc/λ; p=h/λ; number≈rate × exposure.

Remember

Common trap

Interference does not require a photon to deposit energy everywhere on the screen.

Model limits

Fixed detection rate, ideal counter; screen sample uses deterministic quantiles of a four-fringe cos² distribution. It illustrates accumulation, not a simulation of quantum measurement dynamics.

What you will learn

Connect localized photon events with a wave-based probability pattern.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

600 nm photons carry about2.066 eV;20 detections/s for2 s gives40 events.

Why this matters

The model connects photons build an interference pattern with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

Increasing exposure at fixed rate changes the energy of each photon?

It doubles the energy
No; it increases the count
It removes interference

Read the explanation

Energy depends on wavelength; exposure changes how many events are accumulated.

Course connection: Class XII Chapter 11. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.