According to the name wavelength is the length of the wave that is the distance after which the wave repeats itself. Wave has Crests and Troughs. So, distance between two neighbouring troughs or two neighbouring crests are known as Wavelength. Wavelength is represented by lambda “λ”.
Relation with wave speed and frequency,
As, Distance = Speed x time
[Note: We know that, Frequency = 1/time
So, Time = 1/Frequency ]
Hence, Wavelength = Wave speed
Or, λ = V/n
Where, V = Wave speed and
n = frequency
Example 1: Light with a frequency of 5.26 x 10^12 Hz lies in the violet region of the visible spectrum. What is the wavelength of this frequency of light?
Solution: We have given, Frequency, n = 5.26 x 10^12 Hz
And we know that speed of light, V = 3 x 10^8 m/s
As we have relation between wavelength, speed and frequency.
Wavelength = (3 x 10^8)/5.26x10^12
Therefore, Wavelength, λ = 0.27 x 10^-4 m.
Example 2 : Find the wavelength of a wave travelling at 24 m/s at a frequency of 6 Hz.
Solution: By the question we have given,
Wave speed, V = 24 m/s
And frequency, n = 6 Hz
And we have the equation,
Wavelength, λ = Wave Speed/ frequency
= 24/6 = 4 m
Therefore, Wavelength, λ = 4 m