Question

No refraction occurs when the light ray incident is ___ a boundary of two medium.

• A. normal to
• B. parallel to
• C. antiparallel to
• D. curved on

Answer 1

The correct option is A

normal to

When a light wave approaches the boundary in a direction that is not perpendicular to it, then refraction occurs. The transmission of light across a boundary between two media is accompanied by a change in both the speed and wavelength of the wave. So the light incident should not be normal on a boundary of two medium.