Investigating Planck's Constant with LEDs
Planck’s constant (h = 6.626 × 10−34 J·s) is the most fundamental quantity in quantum physics. This classroom resource presents a simple lab activity that allows students to measure Planck’s constant and explore the quantum nature of light (i.e., photons), using light-emitting diodes (LEDs). It aims to make Planck’s constant and quantum physics more tangible and “real” to students.
The resource includes two versions of the lab. The first version is a structured investigation. Students follow instructions to build a simple circuit and make measurements that allow them to measure Planck’s constant. The second version is a guided inquiry activity. Students develop and test a mathematical model in which Planck’s constant is an important proportionality constant.
This is the new edition of our popular Measuring Planck's Constant resource. The new edition is currently available in English and French only.