Advertisements
Advertisements
प्रश्न
In the given figure PQ and PR are the two light rays emerging from an object P. The ray PQ is refracted as QS.
- State the special name given to the angle of incidence ∠PQN of the ray PQ.
- What is the angle of refraction for the refracted ray QS?
- Name the phenomenon that occurs if the angle of incidence ∠PQN is increased.
- The ray PR suffers partial reflection and refraction on the water-air surface. Give reason.
- Draw in the diagram the refracted ray for the incident ray PR and hence show the position of image of the object P by the letter P’ when seen vertically from above.
Advertisements
उत्तर
- ∠PQN Critical angle

- Angle of refraction is 90°.
- The phenomenon is total internal reflection.
-
Because the ray PR's angle of incidence is smaller than ∠PQN (i.e., the critical angle), the ray PR experiences partial reflection and refraction on the water-air surface.

APPEARS IN
संबंधित प्रश्न
Name the factors affecting the critical angle for the pair of media.
What is total internal reflection?
Name the principle on the basis of which optical fibres work.
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
If a ray of light passes from medium I to medium II without any change of direction, what can be said about the refractive indices of these media (angle I is not 0)?
State two advantages of using a right-angle prism as a reflector, rather than a plane mirror.
Answer the following question.
Define the critical angle of incidence and obtain an expression for it.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
