Plancks Constant Apparatus
Product Code : EL-PLE-13149
Eduscope India is a leading Plancks Constant Apparatus
Quick Answer: Planck's Constant Apparatus determines Planck's constant experimentally through the photoelectric effect, using a cesium photocathode and a nanoammeter.
Light striking the apparatus's cesium photocathode ejects electrons, but only when the light's frequency is above a threshold value; measuring how the stopping voltage needed to halt these ejected electrons varies with the light's frequency lets Planck's constant — currently accepted at approximately 6.626 x 10^-34 J.s — be determined directly, a real and historically significant method explained by Albert Einstein in 1905 and cited in his 1921 Nobel Prize in Physics. Three components make the measurement reliable: an enclosed vacuum photocell housing the cesium photocathode, which keeps ejected electrons from being scattered by air molecules, and an attachment for illuminating it with light of known frequency; a high-stability power supply that sweeps a variable stopping voltage until it just cancels the photocurrent at a given frequency; and a nanoammeter sensitive enough to measure the resulting very small photocurrents. Alongside Planck's constant, this Planck constant experiment kit apparatus also estimates the work function of cesium — the minimum energy needed to eject an electron from its surface — to less than 5% error.
| Specification | Value |
|---|---|
| Photocathode | Cesium, in enclosed vacuum photocell |
| Power supply | High-stability, variable stopping voltage |
| Current measurement | Nanoammeter |
| Accuracy | Work function of cesium to <5% error |
EduScope India's physics range, including the Planck's Constant Apparatus, is exported to West African markets such as Nigeria, Ghana, Senegal and Ivory Coast, supporting college and university lab equipping in the region.
This apparatus is also among the physics lab equipment India EduScope India regularly supplies through bulk institutional and government lab-equipment orders, school chains and CSR-funded science-education programs.
It is part of EduScope India's Physics Lab Equipment range, and is a natural companion to the Franck-Hertz Apparatus II and the Hall Effect Apparatus for a broader hands-on foundation in modern physics.
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