Question

define total internal reflection pf light? explain the conditions necessary for its occurence

Answer 1

Total internal reflection is the phenomenon which occurs when a propagated wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary and the incident angle is greater than the critical angle, the wave cannot pass through and is entirely reflected. The critical angle is the angle of incidence above which the total internal reflection occurs. This is particularly common as an optical phenomenon, where light waves are involved, but it occurs with many types of waves, such as electromagnetic waves in general or sound waves.

Answer 2

$\underline \bold{Total\:Internal\: Reflection}$

When the light ray refracts from denser to rare medium, and for a certain angle of incident then the ray travels along the interface of two media by making the angle of reflection equal to right angle.

The angle of incidence for which the reflected ray Travels along the interface of to media is called as Critical Angle.

The phenomena of bouncing back of light ray in the same medium when reflected from denser to rarer medium and falls in the interface that an angle greater to the critical angle for the given pair of media is called as total internal reflection.

The necessary condition of TIR are

• The light must refracts from denser to rare medium.

• The incidence must be above the critical angle for the pair of media.