The phase angle of a point on a periodic wave is the distance between the point and a specified reference point, expressed using an angular measure. This angular measure is obtained by projecting a rotating vector onto the real axis of an Argand diagram. Periodicity is the quality of occurring at regular intervals (e. ... A wave is a disturbance that propagates in a periodically repeating fashion, often transferring energy. ... This article is about angles in geometry. ... The complex numbers are an extension of the real numbers, in which all non-constant polynomials have roots. ...

The phase angle of a vector may be written in angle notation as M ∠θ, where M is the magnitude of the vector and θ is the phase angle relative to the specified reference point. The reference point may be fixed in space, or a point on another periodic wave. In the latter case, the waves may be plotted on a suitable coordinate system, such as a Cartesian plot, with degrees or other angular measure usually plotted on the abscissa and amplitude on the ordinate. Usually, at least one full cycle of each wave is plotted, with 360° (2π radians) encompassing one full cycle. The reference points may be any significant instants on the waves, such as where they cross the abscissa. Angle notation or phasor notation is a notation used in electronics using the ∠ sign. ... A system is an assemblage of inter-related elements comprising a unified whole. ... Abscissa means the x coordinate on an (x, y) graph; the input of a mathematical function against which the output is plotted. ...

For example, in electrical engineering, sinusoidal voltage and current can be expressed as a sine function with a magnitude such as: In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ...

Where φ is the phase angle, V_m is the amplitude, ω is the angular frequency, and t is time.

In many cases, the phase angle is expressed in degrees while the product ωt is usually expressed in radians. A degree (in full, a degree of arc, arc degree, or arcdegree), usually symbolized °, is a measurement of plane angle, representing 1／360 of a full rotation. ... In mathematics and physics, the radian is a unit of angle measure. ...

See Also

• Phasor (electronics)
• Phasor (physics)

See wikibooks book on Phasors A phasor is a complex number representing a sinusoidal function. ... A phasor describes the phase of a particle in a simple harmonic motion or a wave motion. ...

Sources

• Federal Standard 1037C
• Electric Circuits (7th ed) by James Nilsson and Susan Riedel