Total Internal Reflection

1 mark · Normal

Which statement correctly describes total internal reflection in the context of light travelling from glass into air?

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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)

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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.