An optical fibre (mu = 1.72) is surrounded by a glass coating (mu= 1.50). Find the critical angle for total internal reflection at the fibre-glass interface.

A rectangular block of glass (R.l. = 3/2) is kept in water (R.l. = 4/3). The critical angle for total internal reflection between glass and water is

Statement I: A ray is incident from outside on a glass sphere surrounded by air as shown in Figure. This ray may suffer total internal reflection at the second interface. Statement II: For a ray going from a denser to rarer medium, the ray may suffer total internal reflection.

A ray of light strikes a glass plate at an angle of incidence 57^(@) . If the reflected and refracted rays are perpendicular to eachother, calculate critical angle for total internal reflection at glass air interface.

In the diagram shown, a ray of light is incident on the interface between 1 and 2 at angle slightly greater than critical angle. The light surfers total internal reflection at this interface. After that the light ray falls at the interface of 1 and 3, and again it suffers total internal reflection. Which of the following relations should hold true?

A ray of light is incident on a glass prism of refractive index mu and refractive angle A. If it just suffers total internal reflection at the other face, obtain an expression relating the angle of incidence , angle of prism and critical angle.

The path of a ray of light passing through an equilateral glass prism ABC is shown in figure. The ray of light is incident on face BC at the critical angle for just total internal reflection. The total internal reflection. The total angle of deviation after the refraction at face AC is 108^@ . Calculate the refractive index of the glass.

An isosceles glass prism with base angles 40^(@) is champed over a tray of water in a position such that the base is just dipped in water. A ray of light incident normally on the inclined face suffers total internal reflection at the base. If the refractive index of water is 1.33 then the condition imposed on the refractive index mu of the glass is -

Pick out the correct staments about optical fibres from the following: S1: Optical fibres are used for the transmission of optical signals only S2: Optical fibres are used for transmission of optical electrical signals S3: The intensity of light signals sent through optical fibres suffer very small loss S4: Optical fibres effectively employ the principle of multiple total internal reflections S5: Optical fibres are glass fibres coated with a thin layer of a material with lower refractive index