A light ray in air enters and passes through a block of glass.What can be stated with regard to its speed after it emerges from the block?
A)Speed is less than when in glass.
B)Speed is less than before it entered glass.
C)Speed is same as that in glass.
D)Speed is same as that before it entered glass.

Question

Quizplus · Accepted Answer

When a light ray emerges from a block of glass and enters air, its speed returns to the original speed it had before entering the glass. This is because the speed of light in a medium depends on the medium's refractive index, and air has a lower refractive index than glass.

A Light Ray in Air Enters and Passes Through a Block