Total Internal Reflection and Critical Angle
Total Internal Reflection and Critical Angle: Overview
This topic covers concepts, such as, Total Internal Reflection, Critical Angle, Total Internal Reflection in Mirage & Total Reflecting Prisms etc.
Important Questions on Total Internal Reflection and Critical Angle
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

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 and that of refraction is . If the reflected and refracted rays make an angle of with each other, then the critical angle for the pair of media is

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

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?

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)

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

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)

A rod made of glass 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 . Referring to the diagram, is the width of a side & is the radius of the inner semicircle. Find the maximum value of ratio so that, all light entering the glass through surface emerge from the glass through surface .

A room contains air in which the speed of sound is . The walls of the room are made of concrete in which the speed of sound is . (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?

An optical fibre is based on:

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

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

A glass rod of rectangular cross-section is bent into the shape shown in the diagram. A parallel beam of light falls perpendicularly on the flat surface . Determine the minimum value of the ratio for which all light entering the glass through surface will emerge from the glass through surface . The index of refraction of the glass is .

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

The refractive index of a medium decreases with increase in the temperature of the medium.

Mirage is an example of _____ reflection.

At critical angle of incidence, the angle of refraction is _____ degree.

Total internal reflection takes place when the light ray travels from

The refractive index of glass with respect to air is . Then the critical angle of glass-air interface is

Which one has the highest value of critical angle?
