Vernier Software and Technology
Vernier Software & Technology

Planck’s Constant


The energy of a photon is related to its frequency by the equation E = hf, where h is Planck’s constant. By determining the potential required to excite an LED to emit light, you can estimate the energy of the photons emitted. Using a spectrometer, you can measure the peak wavelength of the emitted light; from this, the frequency can be calculated. Performing this analysis for a number of LEDs will enable you to obtain a reasonable approximation of the value of Planck’s constant.


In this experiment, you will

  • Collect and analyze current vs. potential data to estimate the energy required to excite a number of LEDs.
  • Use a spectrometer to determine the wavelength of the peak output of each LED.
  • Determine a value for Planck’s constant from an analysis of the energy and frequency of the light emitted by a number of LEDs.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Advanced Physics with Vernier — Beyond Mechanics

See other experiments from the lab book.

1Behavior of a Gas
2Heat Engines
3Standing Waves on a String
4Standing Waves in a Column of Air
5Doppler Effect
7Coulomb's Law
8Mapping Electric Potential
9Factors Affecting Electrical Resistance
10Series and Parallel Circuits
11Faraday’s Law: Moving Magnet
12Faraday’s Law: Alternating Current
13Capacitors and Inductors
14RLC Circuits
15Curved Mirrors and Images
16Thin Lenses and Real Images
17Thin Lenses and Virtual Images
18Aperture and Depth of Field
21Spectrum of Atomic Hydrogen
22Planck’s Constant

Experiment 22 from Advanced Physics with Vernier — Beyond Mechanics Lab Book

<i>Advanced Physics with Vernier — Beyond Mechanics</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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