Question

defination ofwave number

Answer 1

the number of waves I'm n a unit distance is called wave number

Answer 2

ofwave no. means Wavenumber, sometimes called the propagation number, is in broad terms a measure of spatial scale. It can be thought of as a spatial analog to the temporal frequency, and is often called spatial frequency. It is often defined as the number of wavelengths per unit distance, or in terms of wavelength, λ:
k=1λThe units are m–1, which are nameless in the International System, though cm–1 are called kaysers in the cgs system. The concept is analogous to frequency f, measured in s–1 or Hertz, which is the reciprocal of period T; that is, f = 1/T. In a sense, period can be thought of as a temporal 'wavelength'—the length of an oscillation in time