Critical angle: Can be described as

Critical Angle can be described as the angle of incidence that offers an angle of refraction of 90 degrees. Remember that the critical angle is defined as an angle of incidence value. The critical angle will be 48.6 degrees for water-air boundaries and 61.0 degrees for crown glass-water boundary. The angle of incidence is always larger than the critical angle of the core material with respect to its cladding. Even if the fibre is bent or twisted, the light can easily travel through the fibre. Learn what critical angle is, how to calculate it, and why it is important for total internal reflection. Find out the critical angle values for different pairs of media and their applications in physics and chemistry. The longer and more complete answer: To understand what a critical angle is and why it happens, it is most intuitive to visualize the wave itself. The critical angle can be explained through the context of light (an electromagnetic wave), but refraction and critical angles occur for all types of waves.