English

What is meant by the term ‘critical angle’?

Advertisements
Advertisements

Questions

What is meant by the term ‘critical angle’?

What is a critical angle?

Very Short Answer
Advertisements

Solution

It is the angle of incidence in the denser medium corresponding to which the angle of refraction in the rarer medium is 90°.

shaalaa.com
  Is there an error in this question or solution?

RELATED QUESTIONS

A ray of light travels from water to air as shown in the diagram given below :

1) Copy the diagram and complete the path of the way. Given the critical angle for water is 48°.

2) State the condition so that internal reflection occurs in the above diagram.


Draw diagram to illustrate the total internal reflection.


Calculate the speed of light in a medium whose critical angle is 30° ?


i) Observe the given figure and answer the following questions.
a) Identify and write the natural process shown in the figure.
b) List the phenomena which are observe in this process.
c) Redraw the diagram and show above phenomena in it.


In the following figure, show two rays A and B travelling from water to air. If the critical angle for water- air surface is 48°, complete the ray diagram showing the refracted rays for each. State conditions when the ray will suffer total internal reflection.


How does a ray of light bend when it travels from rarer to denser medium


How does a ray of light bend when it travels from denser to rarer medium.


How are critical angles related to the refractive index of the medium?


Draw a diagram, properly labelled, to illustrate the use of a total reflecting prism (a right-angled isosceles prism) to turn a ray of light through 180°. Name an instrument in which this device is used.


The diagram shows a point source P inside a water container. Three rays A, B, and C starting from P are shown up to the water surface. Show in the diagram the path of these rays after striking the water surface. The critical angle for the water-air pair is 48°.


PQ and PR are two light rays emerging from the object as shown in the figure below:

(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(ii) Copy the ray diagram and complete it to show the position of the image of the object P when seen obliquely from above.
(iii) Name the phenomenon that occurs if the angle of incidence ∠PQN is increased still further.


A spherical marble, of refractive index 1.5 and curvature 1.5 cm, contains a tiny air bubble at its centre. Where will it appear when seen from outside?


Solve Numerical example.

A monochromatic ray of light is incident at 37° on an equilateral prism of refractive index 3/2. Determine angle of emergence and angle of deviation. If angle of prism is adjustable, what should its value be for emergent rays to be just possible for the same angle of incidence?


Critical angle of light passing from glass to air is maximum for ____________.


The resultant `vec"R"` of `vec"P"` and `vec"Q"` is perpendicular to `vec"P"`. Also `|vec"P"|=|vec"R"|`. The angle between `vec"P"` and `vec"Q"` is ______.
[tan 45° = 1]


The twinkling effect of star light is due to ______.


A light is entering from one medium refractive index `("RI" =5/3)` to another medium at an angle 30°. The angle of refraction for other medium is sin-1 `(5/6)`. then the increase in angle of incidence is ______ such that the ray of light reflected back into the same medium.


  • Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
  • Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.

The diagram below shows a fish in the tank and its image seen on the surface of the water.

Name the phenomenon responsible for the formation of this image.


When a ray of light is refracted from one medium to another, then the wavelength changes from 6000 Å to 4000 Å. The critical angle for the interface will be ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×