Physics
Explain the term critical angle with the aid of a labelled diagram.
Answer
When a ray of light passes from a denser to a rarer medium, at a certain angle of incidence i = C, the angle of refraction becomes 90°.
This angle C is called the critical angle.
Thus, critical angle is defined as the angle of incidence in the denser medium corresponding to which the angle of refraction in the rarer medium is 90°.
Related Questions
What is total internal reflection?
Draw diagrams to illustrate critical angle and total internal reflection.
State two conditions necessary for total internal reflection to occur.
Figure below shows two rays A and B travelling from water to air. If the critical angle for water-air surface is 48°, complete the ray diagram showing the refracted rays for each. State conditions when the ray will suffer total internal reflection.
