Wave Terminology

Terms and symbols used to describe waves.

Wavelength λ , meter(m):

The wavelength of a wave is the smallest distance between two points that have the same pattern of oscillation. It is also the distance the wave travels before the pattern repeats itself. 

Period T , second(s):

The period of a wave is the time for one complete pattern of oscillation to take place at any  point.

Frequency f , hertz(Hz):
The frequency of a wave is the number of oscillations per unit time at any point. 

 Frequency=1/Period.

   

Displacement x , meter(m):

Displacement is the distance any part of the wave has moved from its mean (or rest) position it can be positive or negative.

Phase difference  Φ , rad:

The angular displacement of two points on a wave of identical frequency in terms of how much one wave leads another     

Phase difference concerns the relationship between the pattern of vibration at two points. Two points that have exactly the same pattern of oscillation are said to be "in phase"- there is "zero"

phase difference between them. If the pattern of movement at the two points is exactly opposite to one another, the the waves are said to be in "antiphase", they are half cycle different to one another.

The angle for one complete rotation of the vector arrow is 2π radians.

Waves that are in antiphase are π radians out of phase.

One revolution =circumference of circle

                              radius of circle

2πr  =2π radian

  r

From this we can deduce

360°=2π

180°=π

90°=π/2

     

     

In phase

 
 

Antiphase

By Harshil