The Kappa (Greek neuter Κάππα, majuscule Κ, κ minuscule or κ ) is the 10th letter of the Greek alphabet and has after the Milesian principle a numerical value of 20


In physics, the symbol for various physical quantities is used. It is on the one hand, the symbols for the electrical conductivity, thermal conductivity, for the kinematic viscosity and the other, the symbols of the compressibility. Sometimes the symbols is also used for the isentropic exponent.

In mathematics, the symbol is used to indicate the curve.

In psychology, the symbol for Cohen's Kappa is used as a measure of inter -rater agreement.

In medicine ( plasmacytoma and precursors ) are divided paraproteins ( incomplete immunoglobulins) for differentiation and measurement in kappa and lambda proteins in monoclonal gammopathy. Moreover, there are in the field of action of glucocorticoids ( steroid hormone) intracellular, receptor-binding proteins ( NF-κB/Iκ-B ), which are also labeled with that letter.