Question
A student traces the path of a ray of white light through a rectangular glass slab and marks, the angles of incidence (∠i) , refraction (∠r) and emergence (∠e) as shown. Which angle or angles has he not marked correctly?
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∠i only
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∠i and ∠r
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∠i and ∠e
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∠r and ∠e
Solution
C.
∠i and ∠e
Incident and emergent angles are always measured from the normal of the plane.
