Negative frequency Negative frequency The concept of negative and positive frequency can be as simple as a wheel rotating one way or the other way: a "signed value" of frequency can indicate both the rate and direction of rotation. The rate is expressed in units such as revolutions (a.k.a. "cycles") per second (hertz) or radian/second (where 1 cycle corresponds to 2"π" radians). Let "ω" be a nonnegative parameter with units of radians/sec. Then the angular function (angle vs. time) , has slope −"ω", which is called a negative frequency. But when the function is used as the argument of a cosine operator,
Ohm Ohm The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm. Although several empirically derived standard units for expressing electrical resistance were developed in connection with early telegraphy practice, the British Association for the Advancement of Science proposed a unit derived from existing units of mass, length and time and of a convenient size for practical work as early as 1861. The definition of the ohm was revised several times. Today, the definition of the ohm is expressed from the quantum Hall effect. The ohm is defined as an electrical resistance