Time taken by the sunlight to pass through a slab of thickness 4 mm and refractive index 1.5 is sec.

Question

Accepted Answer

(3) 2×10⁻¹¹. Given: thickness t=4 mm=4×10⁻³ m, refractive index n=1.5. Idea: inside the glass light travels at v=c/n, so the time to cross is t/v. v=(3×10⁸)/(1.5)=2×10⁸ m s⁻¹. Transit time =(4×10⁻³)/(2×10⁸). So the light is inside the slab for 2×10⁻¹¹ s, about twenty picoseconds.

Time taken by the sunlight to pass through a slab of thickness 4 mm and refractive index 1.5 is ______ sec.

Step-by-step solution

Why the other options are wrong