# Kappa: Wikis

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# Encyclopedia

Variant kappa
 Greek alphabet Obsolete letters Other characters Αα Alpha Νν Nu Ββ Beta Ξξ Xi Γγ Gamma Οο Omicron Δδ Delta Ππ Pi Εε Epsilon Ρρ Rho Ζζ Zeta Σσς Sigma Ηη Eta Ττ Tau Θθ Theta Υυ Upsilon Ιι Iota Φφ Phi Κκ Kappa Χχ Chi Λλ Lambda Ψψ Psi Μμ Mu Ωω Omega Digamma Qoppa San Sampi Stigma Sho Heta Greek diacritics

Kappa (uppercase Κ, lowercase κ or ϰ; Greek: Κάππα) is the 10th letter of the Greek alphabet, used to represent the voiceless velar stop, or "k", sound in Ancient and Modern Greek. In the system of Greek numerals it has a value of 20. It was derived from the Phoenician letter Kaph. Letters that arose from kappa include the Roman K and Cyrillic К.

Greek proper names and placenames containing kappa are often written in English with "c" due to contemporary rendering into the Latin alphabet by ancient Romans. However, modern transliteration of the Greek language invariably use the letter "k". Compare Κυνοσκεφαλαι, Cynoscephalae (ancient placename); κυνος κεφαλαι, kunos kephalai (phrase), meaning "dog's heads".

Greek word καί written with a handwritten variant of kappa, from the Byzantine period

In mathematics, the kappa curve is named after this letter; the tangents of this curve were first calculated by Barrow (17th Century).

## Symbol

In graph theory, the connectivity of a graph is given by κ.

In differential geometry, the curvature of a curve is given by κ.

In physics, the torsional constant of an oscillator is given by κ.

In structural design, κ is the ratio of the smaller factored moment to the larger factored moment and is used to calculate the critical elastic moment of an unbraced steel member.

In chemistry, the compressibility of a compound is given by κ.

In psychology and psychiatry, kappa represents a measure of diagnostic reliability.

In biology, kappa and kappa prime are important nucleotide motifs for a tertiary interaction of group II introns.

In biology, kappa designates a subtype of an antibody component.

In pharmacology, kappa represents a type of opioid receptors.

In chemistry, kappa represents the element potassium.

Kappa statistics such as Cohen's kappa and Fleiss' kappa are methods for calculating inter-rater agreement.

Upper-case letter Κ is used as a symbol for:

In textual criticism, the Byzantine text-type (from Κοινη, Koine, the common text).

In set theory, kappa is often used to denote an ordinal which is also a cardinal.

# Wiktionary

Up to date as of January 15, 2010

## German

German Wikipedia has an article on:
Kappa

Wikipedia de

### Noun

Kappa n.

1. kappa (Greek letter)

# Simple English

Kappa may be:

Kappa may be short for:

• Kappa Alpha Psi
• Kappa Kappa Gamma
• Kappa Kappa Kappa
• Kappa Phi Lambda