Total Internal Reflection

IMPORTANT

Total Internal Reflection: Overview

This topic covers concepts such as Total Internal Reflection, Critical Angle, Total Internal Reflection in Liquids and Total Internal Reflection in Optical Fibers etc.

Important Questions on Total Internal Reflection

EASY
IMPORTANT

A beam of light consisting of red, green and blue and is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelength are 1.39, 1.44 and 1.47 respectively. The prism will

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MEDIUM
IMPORTANT

A ray of light traveling in a denser medium strikes the boundary of a rarer medium and gets partially reflected and refracted. The angle of reflection is r and that of refraction is r'. If the reflected and refracted rays make an angle of 90° with each other, then the critical angle for the pair of media is

HARD
IMPORTANT

Two glass blocks of triangular cross section(n=1.5) are used to make a periscope. Which of the following is the correct arrangement?

HARD
IMPORTANT

A vertical parallel beam of rays comes from bottom of a tank filled with a liquid. When it is accelerated with an acceleration of 7.5 m/s2, the ray is seen to be totally reflected by liquid surface. What is minimum possible refractive index of liquid?

HARD
IMPORTANT

A point source of light is placed at a distance h below the surface of a large deep lake. What is the percentage of light energy that escapes directly from the water surface is μ of the water = 4/3? (neglect partial reflection)

MEDIUM
IMPORTANT

A small source of light is 4 m below the surface of a liquid of refractive index 5/3. In order to cut off all the light coming out of liquid surface, minimum diameter of the disc placed on the surface of liquid is

EASY
IMPORTANT

In the figure ABC is the cross section of a right angled prism and BCDE is the cross section of a glass slab. the value of θ so that light incident normally on the face AB does not cross the face BC is (given sin-1 (3/5) = 37o)

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HARD
IMPORTANT

A rod made of glass (μ=1.5) and of the square cross-section is bent into the shape shown in the figure. A parallel beam of light falls perpendicularly on the plane flat surface A. Referring to the diagram, d is the width of a side & R is the radius of the inner semicircle. Find the maximum value of ratio dR so that, all light entering the glass through surface A emerge from the glass through surface B

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HARD
IMPORTANT

A room contains air in which the speed of sound is 340 m s-1. The walls of the room are made of concrete in which the speed of sound is 1700 m s-1. (a) Find the critical angle for total internal reflection of sound at the concrete - air boundary. (b) In which medium must the sound be travelling to undergo total internal reflection?

EASY
IMPORTANT

An optical fibre is based on:

MEDIUM
IMPORTANT

A ray of light from a denser medium strikes a rarer medium at an angle of incidence i (see figure). The reflected and refracted rays make an angle of 90° with each other. The angles of reflection and refraction are  r and r'  The critical angle is

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MEDIUM
IMPORTANT

A ray of light from a denser medium strikes a rarer medium at an angle of incidence i (see figure). The reflected and refracted rays make an angle of 90° with each other. The angles of reflection and refraction are  r and r'. The critical angle is

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EASY
IMPORTANT

A glass prism of refractive index 1.5 is immersed in water (refractive index 43). A light beam incident normally on the face AB is totally reflected to reach on the face BC if

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EASY
IMPORTANT

What is TIR?

EASY
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What is the maximum angle of incidence 'i' for which total internal reflection take place inside the pipe as shown in the figure?

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EASY
IMPORTANT

Light travels a distance x in time t1 in air and 10x in time t2 in another denser medium. What is the critical angle for this medium?

EASY
IMPORTANT

The critical angle for a denser-rarer interface is 45°. The speed of light in rarer medium is 3×108 m s-1. The speed of light in the denser medium is:

MEDIUM
IMPORTANT

If light is passing through a medium of critical angle 45o, then the wave speed will be

EASY
IMPORTANT

The critical angle for the total internal reflection of diamond in air is24° . State whether the statement given here is correct or incorrect. Give a reason for your answer.

The sparkle of the diamond increases remarkably when placed in water.

EASY
IMPORTANT

The critical angle for the total internal reflection of diamond in air is 24°. State whether the statement given here is correct or incorrect. Give a reason for your answer.

The critical angle for total internal reflection of diamond is more than 24° when surrounded by water.