An electrical contact is an electrical circuit component found in electrical switches, relays and breakers. It is composed of two pieces of electrically conductive metal that pass electrical current or insulate when the gap between them is closed or open.
noun. Schwa is a vowel sound in an unstressed syllable, or the phonetic symbol É which is the International Phonetic Alphabet symbol for schwa. An unstressed syllable in a word, such as the a syllable in ago, is an example of schwa.oun. 1  A mid-central neutral vowel, typically occurring in unstressed syllables, as the final vowel of English sofa. 2  The symbol (&schwa;) used to represent an unstressed neutral vowel and, in some systems of phonetic transcription, a stressed mid-central vowel, as in but.
crack - a sudden sharp noise; the crack of a whip; he heard the cracking of the ice; he can hear the snap of a twig cracking, snap noise - sound of any kind (especially unintelligible or dissonant sound); he enjoyed the street noises; they heard indistinct noises of people talking; during the firework display that ended the gala the noise reached 98 decibels