Question
The time required for light to pass through a glass slab (refractive index = 1.5) of thickness 4 mm is ........ ($c = 3 \times 10^8 \, \text{m s}^{-1}$, speed of light in free space).
The time required for light to pass through a glass slab (refractive index = 1.5) of thickness 4 mm is ........ ($c = 3 \times 10^8 \, \text{m s}^{-1}$, speed of light in free space).