Question

The frequency of a wave of light is $12\times {10}^{14}{s}^{-1}$ . The wave number associated with the light is

• A. 5 × 10^-7m
• B. 4 × 10^-8 cm^-1
• C. 2 × 10^-7 m^-1
• D. 4 × 10⁴ cm^-1

Answer 1

The correct option is D

4 × 10⁴ cm^-1

Frequency $v$ = $12\times {10}^{14}{s}^{-1}$ and velocity of light

$c$ = $3\times {10}^{10}cm{s}^{-1}$. We know that the wave number $\overline{v}=\frac{v}{c}=\frac{12\times {10}^{14}}{3\times {10}^{10}}=4\times {10}^{4}c{m}^{-1}$