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 𝜃1 = 41. We also know that 𝜃2 = 90 degrees because it is the critical angle which is the point at which the angle of refraction is 90 degrees. sin90 = 1 so 𝑛1 sin 𝜃1 = 𝑛2 sin 𝜃2 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.

MS
Answered by Marnie S. Physics tutor

14384 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

I throw a ball straight up with an initial velocity of 2m/s. How high is it after a fifth of a second?


Waves on the surface of water are transverse waves. State one other example of a transverse wave.


What is the difference between a scalar and a vector?


An Electric Kettle is used to boil water. After the water is boiled, the temperature of the water decreases by 22C. The mass of water in the kettle is 0.50 kg. The specific heat capacity of water is 4200 J/kg C. Calculate the energy transferred.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences