Question

What would be the frequency of the wave if it has wavelength of $100\text{nm}$?
Speed of light = $3\times {10}^8\text{m/s}$

• A. $3\times {10}^3\text{Hz}$
• B. $3\times {10}^{13}\text{Hz}$
• C. $3\times {10}^8\text{Hz}$
• D. $3\times {10}^{15}\text{Hz}$

Answer 1

The correct option is D $3\times {10}^{15}\text{Hz}$

Data given in the question:
Wavelength = $100\text{nm}$ =$100\times {10}^{-9}\text{m}$ = ${10}^{-7}\text{m}$
Speed of light = $3\times {10}^8\text{m/s}$

The relation between frequency and wavelength of a wave is:
Frequency (v) × Wavelength (λ) = Speed of light(c)
$\text{v}$ = $\frac{c}{\lambda }=\frac{3\times {10}^8}{{10}^{-7}}$
= $3\times {10}^{15}\text{Hz}$