Total Internal Reflection
1 mark · NormalWhich statement correctly describes total internal reflection in the context of light travelling from glass into air?
Show answer
Correct option: It occurs when the angle of incidence is greater than the critical angle.
Common mistakes: Selecting 'less than' instead of 'greater than' the critical angle; Confusing direction (glass to air vs air to glass)
Show mark scheme and worked solution
Marking points
A1 · 1 mark · Correctly identifies 'greater than the critical angle' as the condition for total internal reflection.
Worked solution
Total internal reflection occurs only when the angle of incidence is greater than the critical angle for the boundary.