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प्रश्न
Total internal reflection can take place only if ______.
विकल्प
light goes from an optically rarer medium (smaller refractive index) to optically denser medium
light goes from optically denser medium to rarer
mediumthe refractive indices of the two media are close to each other
the refractive indices of the two media are widely different.
उत्तर
Total internal reflection can take place only if the light goes from an optically denser medium to a rarer medium.
Explanation:
The angle of incidence is greater than the critical angle.
APPEARS IN
संबंधित प्रश्न
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is ______.
What is total internal reflection?
State two conditions necessary for total internal reflection to occur.
Total internal reflection occurs only when a ray of light passes from a ______ medium to a ______ medium.
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.
The observation made by Swarali while doing the experiment is given below. Based on these write answers to the questions:
Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium.
Questions:
- What is the specific value of∠i called?
- What is the process of reflection of incident rays into denser medium called?
- Draw the diagrams of three observations made by Swarali.
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
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.
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.
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?
Answer the following question.
Explain ‘mirage’ as an illustration of refraction.
Answer the following question.
Define the critical angle of incidence and obtain an expression for it.
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?
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]
For the same angle of incidence, the angle of refraction in four media A, B, C and D are 25°, 30°, 35° and 40° respectively. The speed of light is least in medium ______.
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)
The outer concentric shell in optic fiber is called ______.
Which of the following statements about total internal reflection is true?
The angle of incidence at which the angle of refraction is Q£ is called the critical angle.
