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For Students · Double-Slit

Double-Slit for a see-saw balance

Built for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition. Simulate a see-saw balance live below — adjust the inputs and watch it respond, right in your browser.

Double-Slit ExperimentLive

wave interference + diffraction

Controls

The iconic experiment: two slits create interference fringes, modulated by each slit's diffraction envelope.

Presets

Slit separation d

Slit width a

Wavelength λ

▶ Run in Python

Data Inspector

Fringe spacing∝ λ/d

Envelope∝ λ/a

Regimeinterference-dominated

Governing equation

I = I_{0} cos^{2} \frac{π d sin θ}{λ} sinc^{2} \frac{π a sin θ}{λ}, Δ y = \frac{λ L}{d} = \frac{20 \cdot 800}{40} = 400

Reading this result: Two-slit interference sets the fine fringe spacing (∝ λ/d) while single-slit diffraction sets the envelope (∝ λ/a); here about 10 bright fringes fit under the central peak.

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Frequently asked questions

Is this good for students?: Yes — this version of "Double-Slit for a see-saw balance" is framed for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.