d) Total internal reflection

e) critical angle; sinC  = 1/n; total internal reflection for light

total internal reflection = when light hits a boundary and completely reflects within the original medium

critical angle = angle of incidence that causes the angle of refraction to be 90°

conditions

• light travels from a medium with a high refractive index to the boundary of a medium with a low refractive index

• incident angle > critical angle

when light hits the boundary of air

sinC = 1/n

• sine of the critical angle (°) = 1 / refractive index of the reflective medium