H

Symbol for henry, the SI unit of inductance, equal to the inductance of a closed circuit with a magnetic flux of 1 weber per ampere of current.

H

Eighth letter of the English alphabet, representing an aspirate in all modern alphabets derived from the Latin except in those languages, especially the Romance languages, where the aspirate is dropped. It is used in several diagraphs (conventional two-letter sequences with special values), such as ch, gh, ph, sh, and th.

In English h can be pronounced, as in ‘harm’ and ‘house’; be silent, as in ‘hour’ and ‘honest’ (and sometimes in words such as ‘hotel’ and ‘historical’); or be used in a diagraph, as in ‘church’, ‘ghost’, ‘phrase’, ‘shed’, and ‘thin’.

It was called heth or kheth in the Semitic, Greek, Etruscan, and Latin alphabets from which it is derived. The Semites used it as an unvoiced velar fricative; today it is an unvoiced glottal fricative. The Greeks used it either to represent a vowel, or for the aspirate; the aspirate h passed into the Roman alphabet. In popular spoken Latin the sound /h/ was commonly dropped, as in some current English accents.

H

In music, the German equivalent of B natural.