The speed of the yellow light in a certain liquid is $2.4\times {10}^8{\mathrm{ms}}^{-1}$. Find the refractive index of the liquid.

The wavelength range of the light that is visible to an average human being is $400\mathrm{nm}$ to $700\mathrm{nm}$. What is the frequency range of this light?

Red Light of wavelength $750 \mathrm{nm}$ enters a glass plate of refractive index $1.5$. If the velocity of light in vacuum is $3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$, magnitude of frequency glass is $n\times {10}^{14} \mathrm{Hz}$. Value of $n$ is  

Red Light of wavelength $750\mathrm{nm}$ enters a glass plate of refractive index $1.5$. If the velocity of light in vacuum is $3\times {10}^8{\mathrm{ms}}^{-1}$, calculate in the glass velocity of light in ${10}^8 \mathrm{m}/\mathrm{s}$.

Red Light of wavelength $750\mathrm{nm}$ enters a glass plate of refractive index $1.5$. If the velocity of light in vacuum is $3\times {10}^8{\mathrm{ms}}^{-1}$, calculate in the glass wavelength of light in $\mathrm{nm}$.