Planck's constant is used in which field of study?

Planck's constant is a fundamental quantity in the field of quantum mechanics. It denotes the size of the smallest measurable quantities in phenomena at the atomic and subatomic levels. Specifically, it relates the energy of a photon to its frequency through the formula E = hf, where E is energy, h is Planck's constant, and f is the frequency of the radiation. This relationship highlights the wave-particle duality of light and is a cornerstone of quantum theory.

The significance of Planck's constant extends to various applications, including explaining the photoelectric effect, the quantization of energy levels in atoms, and the behavior of particles and waves at microscopic scales. In essence, it allows us to understand that energy is not continuous but instead exists in discrete units, or quanta, which is a fundamental concept in quantum mechanics.

While Planck's constant might have implications in thermodynamics, classical mechanics, or nuclear physics, its primary application and the theoretical basis arise from quantum mechanics. As such, it is primarily associated with this field of study.