Advertisements
Advertisements
Question
Total internal reflection can take place only if ______.
Options
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.
Advertisements
Solution
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
RELATED QUESTIONS
You are given prisms made of crown glass and flint glass with a wide variety of angles. Suggest a combination of prisms which will
(a) deviate a pencil of white light without much dispersion,
(b) disperse (and displace) a pencil of white light without much deviation.
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.
How does a ray of light bend when it travels from when it is normal to the interface of the two media.
What is meant by the term ‘critical angle’?
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?
Which of the following is not involved in formation of a rainbow?
Describe the construction and working of an optical fibre.
Answer the following question.
What are the advantages of optical fibre communication over electronic communication?
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 ______.
For a ray of light, the critical angle is minimum when it travels from ______.
The twinkling effect of star light is due to ______.
A particle is projected such that the horizontal range and vertical height are equal. Then the angle of projection is :
What is a mirage? How does it occur?
What is the phenomenon used in optical fiber? Explain.
A green light is incident from the water to the air-water interface at the critical angle (θ). Select the correct statement.
State the condition under which total internal reflection occurs. Give the mathematical expression for total internal reflection.
