The wavelength of light in vacuum is λo . When it travels normally through glass of thickness t . Then find the number of waves of light in ‘ t ’ thickness of glass .

Q: The wavelength of light in vacuum is λo . When it travels normally through glass of thickness ‘t’. Then find the number of waves of light in ‘t’ thickness of glass (Refractive index of glass is μ) .

Sol: Number of waves in a thickness ‘t’ of a medium of refractive index μ is

Number of waves = thickness/wavelength = t/λm

But , $\large \lambda_m = \frac{\lambda_o}{\mu}$

Number of waves $\large = \frac{\mu t}{\lambda_o}$

Where λo is the wavelength of light in vacuum.