In this article we are learning about the wavelength concept. Wavelength is nothing but the distance between the crest and crest in a wave or the distance between the trough and trough in a wave. Crest is the peak of the wave and trough is the lowest dip of the wave. It is denoted by the symbol lambda(?). ]
Formula for Wavelength is an important term which helps to study about the characteristic of a given wave. The distance among two successive points on a wave is called wavelength, those two points may be two consecutive peaks or zero crossing or even midpoints of a cycle. The follow figure helps you to know about it much better.
WavelengthFormula – wavelength and frequency:Formula for frequency:f = 1 / TWhere T is the time of one wave period in seconds and f is the frequency in Hz.Formula for wavelength:? = v / f? (lambda) = wavelength in feetV = velocity of propagation in feet per second.f is the frequency in Hz.Conversion of frequency to wavelength:f = v / ?Conversion of wavelength to frequency:? = v / f
Example problems:Example 1: What will be the frequency in case where the time taken to complete one revolution is 0.7 second?Solution:Formula to find frequency:f = 1/Tf = 1/0.7 = 1.4285 HzExample 2: Calculate wavelength of light when the frequency is 100 Hz.Solution:Formula to find Wavelength using frequency:? = v/fGiven: f = 100 HZWe know the velocity of light is constant. That is v = 299,792,458 m/s.? = 299,792,458 / 100 = 2997924.58 sec
Example 3: The light has a wavelength of 500 m, find the frequency of the light.Solution:The relation between frequency and wavelength is f = v / ?Speed of light = v="3" x 108 m/sWave length = ? = 500 mFrequency = f = v / ?= (3 x 108) /500Frequency = 60 x 10 4 Hz