If ray travelling in air is incident on a transparent medium as shown in the diagram, the refractive index of the medium is given as
-
cosα / sinβ
- sinα / sinβ
- cosβ / sinα
- sinβ / sinα
The correct answer is: A
Explanation
\(n = \frac{sin i}{sin r}\)
\(i = 90 - \alpha\)
\(\therefore n = \frac{sin 90 - \alpha}{sin \beta}\)
⇒ \(n = \frac{cos \alpha}{sin \beta}\)
There is an explanation video available .