Question

What is the SI unit of wave number?

• A. m
• B. m^-1
• C. s
• D. s^-1

Answer 1

The correct option is B

m^-1

Explanation for correct option:

1. It is defined as the number of waves present per unit distance.
2. It is the reciprocal of wavelength, $k=\frac{1}{\lambda }$, where, $k$ = wave number, $\lambda$= wavelength.
3. $m^{-1}$ is the SI unit of wavenumber.

Explanation for incorrect options:

1. $m$ is the SI unit of length.
2. $s$ is the SI unit of time.
3. $s^{-1}$ is the SI unit of frequency.

Hence, option (b) is correct.