91影视

he number of waves that moves a fixed point in unit time is known as frequency.

$\mathrm{f}=\frac{1}{\mathrm{T}}\mathrm{or}\frac{\mathrm{蝇}}{2\mathrm{蟺}}$

Where,T =Time period in seconds and is angular frequency in .

The frequency, wavelength, and speed of light of any wave are related by the wavelength-frequency relationship.

The wavelength-frequency relationship is:

$c=位f$

Where, c is the speed of light which is equal to localid="1664349940163" $3脳{10}^8\mathrm{m}/\mathrm{s},\mathrm{位}$is the wavelength and is the frequency.

The wavelength is inversely proportional to the frequency.

$位=\frac{c}{f}or\frac{v}{f}$

Where, v is velocity of wave in m/s.

The relation between wave number and wavelength is:

$k=\frac{2蟺}{位}$

Where, k is wavenumber in rad/m.

Given that,

$$\begin{gathered} \mathrm{v}=2.17脳{10}^8\mathrm{m}/\mathrm{s} \\ \mathrm{f}=5.70脳{10}^{14}\mathrm{Hz} \end{gathered}$$

The wavelength of glass is

$$\begin{gathered} {\mathrm{位}}_{\mathrm{glass}}=\frac{\mathrm{v}}{\mathrm{f}} \\ =\frac{2.17脳{10}^8}{5.70脳{10}^{14}} \\ =3.81脳{10}^{-7}\mathrm{m} \end{gathered}$$

The wavelength of air is

$$\begin{gathered} {\mathrm{位}}_{\mathrm{air}}=\frac{\mathrm{c}}{\mathrm{f}} \\ =\frac{3脳{10}^8}{5.70脳{10}^{14}} \\ =5.26脳{10}^{-7}\mathrm{m} \end{gathered}$$

Hence, wavelength of a wave of the wave in the glass is $3.81脳{10}^{-7}$mand the wavelength of a wave of the wave in the air is $5.26脳{10}^{-7}\mathrm{m}$.

The refractive index of glass is:

$$\begin{gathered} \mathrm{n}=\frac{\mathrm{c}}{\mathrm{v}} \\ =\frac{3脳{10}^8}{2.17脳{10}^8} \\ =1.38 \end{gathered}$$

And the dielectric constant for glass is:

$$\begin{gathered} K=n^2 \\ =1.{38}^2 \\ =1.90 \end{gathered}$$

Hence, index of refraction n of the glass for an electromagnetic wave with $5.70脳{10}^{14}\mathrm{Hz}$frequency is 1.38 and the dielectric constant for glass at $5.70脳{10}^{14}\mathrm{Hz}$frequency is 1.90 .