Monochromatic light of frequency 6 10¹⁴ Hz in vacuum enters a glass slab of thickness 2.0 mm and refractive index 1.5 . The number of complete waves contained within the thickness of the glass slab is : (Speed of light in vacuum c = 3 10^8 m/s )

Step-by-step solution

First, find the wavelength of the light in vacuum ( _ vacuum ): _ vacuum = c f = 3 10^8 6 10¹⁴ = 0.5 10⁻⁶ m When the light enters the glass slab, its wavelength decreases. The wavelength in the medium ( _ medium ) is: _ medium = _ vacuum = 0.5 10⁻⁶ 1.5 = 1 3 10⁻⁶ m The number of complete waves ( N ) contained within the thickness ( t ) of the slab is the total thickness divided by the wavelength in that medium: N = t _ medium = 2.0 10⁻³ 1 3 10⁻⁶ N = 2.0 10⁻³ 3 10^6 = 6 10^3 = 6000 Answer: 6000