What is the difference between Phasor and Vector?

Answer 1

Phasors are actually vectors but they represent something specific. Vectors can be used in many situations to represent anything that has magnitude and direction, and in any number of dimensions. Vectors can be used for exactly what phasors are used for, but use of the word 'phase' in 'phase-vector' or 'phasor' carries with it, some implied information:

A phase-vector specifically represents a sinusoid by implying in it, a frequency of rotation about the origin point. A single phasor thus has an implied circular locus. The relevance of the angle is with respect to other phasors drawn in the same diagram and the conventional reference is what you would normally draw as the positive horizontal x axis on a common graph. Phase angles are measured in an anti-clockwise direction from that line. A phasor is actually drawn in the Argand plane which accommodates complex numbers. Therefore every location in the Argand plane can represent a phasor typically in one of the following forms:

R + j X , R is the real-component and X is the imaginary component

|Z|eja , where a s the phase angle (radians), Z is the magnitude of the vector.

A( cos(wt) + j sin(wt) ), where w = 2 pi f

f = frequency

A = amplitude

Note: phasors are often used in electronic engineering so the symbol j is used

to represent sqrt(-1). In pure mathematics, the symbol i is used.

The advantage of encoding so much information into the phasor is that it makes

possibly difficult calculations into simple vector additions.

For example, it is possible to consider a long phasor as a static reference on the diagram (even though it is implied to be rotating), and place on it's point, another small phasor that rotates compared to the reference. In this case, the dynamic vector sum of the phasors will describe something known as the 'capture effect' in FM radio.

Answer 2

A vector is a physical quantity that has both magnitude and direction (x, y, z; or polar coordinates). A phasor is a mathematical quantity created in electronics to explain AC behavior; it has magnitude and phase (units in degrees or radians). The phase has nothing to do with the angle in polar coordinates.

Alternative AnswerA phasor is a rotating vector. Whereas a vector represents quantity and direction, a phasor represents quantity and displacement measured in a counterclockwise direction. Phasors are used in electrical engineering to represent certain AC quantities -e.g. the relationship between current and voltage.