The critical angle for a glass is 41 degrees. Calculate its refractive index.
Firstly we must remind ourselves of what is meant by critical angle. The critical angle is the angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflected (easily represented on a diagram).
So in our equation for refraction we can substitute in n2 = 1 (because air has a refractive index of 1) and π1 = 41. We also know that π2 = 90 degrees because it is the critical angle which is the point at which the angle of refraction is 90 degrees. sin90 = 1 so π1 sin π1 = π2 sin π2 becomes n1 x sin41 = 1. So the refractive index of the glass (n1) = 1/sin41 = 1.524. Because we have only been given information to two significant figures in the question, we leave our answer as 1.5.
Related Physics GCSE answers
All answers βΈExplain, with reference to the Schwarzschild radius, why the sun isnβt a black hole.
A note was played on an electric keyboard. The frequency of the note was 440Hz. What does a frequency of 440 Hz mean?
If a boy is stationary on a skateboard and jumps off forwards, why does the skateboard move backwards?
Describe (both quanititavely and qualitiatively) the energy changes of a ball of mass 0.5kg, dropped from a height of 10m and left to bounce. Make use of the law of conservation of energy.