Tag: option a: relativity

Questions Related to option a: relativity

A certain color of light towards the purple end of the visible spectrum has a wavelength of $420\ nm$ in a vacuum.
What is the frequency of this light?
The speed of light in a vacuum is $3.00\times 10^8 m/s$

physics option a: relativity the nature of light speed of light and optical density introduction to light

  1. $126 Hz$

  2. $1.26\times 10^{11}Hz$

  3. $7.1\times 10^{14}Hz$

  4. $1.4\times 10^{-15}Hz$

  5. $1.4\times 10^{-6}Hz$

Show answer
Correct Option: C
Explanation:

Given :   $v = 3.00 \times 10^8$  m/s                 $\lambda = 420$ nm $ = 420 \times 10^{-9}$  m

$\therefore$ Frequency of the light       $\nu = \dfrac{v}{\lambda} = \dfrac{3.00 \times 10^8}{420 \times 10^{-9}} = 7.1 \times 10^{14}$  $Hz$