Given, wavelength of blue light in vacuum,
λa=450nm=450×10−9m Refractive index of medium,
µm=1.5 Speed of light in air or vacuum,
c=3×108m∕s λm is the wavelength of light in medium.
whereas
vm is the speed of light in medium.
As we know that,
Refractive index of medium with respect to air,
µma‌‌=‌=‌ ∴‌‌λm‌‌=‌ ‌‌=450×10−9×‌=‌×10−9 ‌‌=3×10−7m ‌ Since, ‌‌‌‌=‌ ⇒‌‌vm‌‌=c‌=3×108×‌ =‌‌2×108ms−1 Since,
‌‌fm=‌ where,
fm is frequency of light in medium.
∴‌fm‌‌=‌ ⇒‌fm‌‌=‌=0.66×1015 ‌‌=6.67×1014Hz