# Total Internal Reflection

Flashcards by 18ivytam, updated more than 1 year ago
 Created by 18ivytam about 5 years ago
102
2

### Description

what total internal reflection is and how to calculate it.

## Resource summary

 Question Answer What is total internal reflection (TIR)? Total Internal Reflection is when a light ray is reflected back into the medium it went in. Thus, the ray is unable to be seen from the other side. What must happen in order for TIR to occur? (name 2 conditions) 1. Angle of incidence> critical angle 2. The light ray must pass from a medium with a higher refractive index than the medium it ends in. Thus ni > nr. Light passes through a slow (dense) medium to a faster(less dense) medium. How do you calculate refractive index? n = sin i / sin r i = angle of incidence r= angle of refraction What is the critical angle? The critical angle is the angle of incidence produces an angle of refraction at 90 degrees. Different mediums have different critical angles. How do you calculate the critical angle? sin c = n r / n i n r = the refractive index of the medium the ray passed INTO. n i = the refractive index of the medium the ray STARTED in. How do you calculate the critical angle of which the light ray passes from a medium into AIR? sin c = 1/ni Since the refractive index of air is 1. What are the uses of total internal reflection (TIR)? Telecommunications ( Cable TV, Local area networks, CCTV) Medical use of Endoscopes Astronomy What do mediums with a high refractive index usually have (critical angle)? Mediums with a high refractive index usually have a low critical angle, thus T.I.R occurs a lot. For example diamonds diamonds have a low critical angle and thus T.I.R occurs more often which makes it appear sparkly. Define angle of incidence and angle of refraction. Angle of incidence is the angle between an incident ray and the normal. Angle of refraction is the angle between a refracted ray and the normal. What is refractive index? Refractive index of a material is a measure of the change in speed of light as it passes from a vacuum into the material.

### Similar

Using GoConqr to study science
GCSE AQA Physics - Unit 3
AQA Physics P1 Quiz
GCSE AQA Physics 1 Energy & Efficiency
Waves
Forces and their effects
Forces and motion
Junior Cert Physics formulas
OCR Physics P4 Revision