Question

Ray optics is valid when characteristic dimension are

• A. much smaller than wavelength of light
• B. of same order as wavelength of light
• C. much larger than wavelength of light
• D. none of the above

Answer 1

The correct option is C

much larger than wavelength of light

Ray optics:

1. It is a geometrical optics.
2. It is an optics in which light propagates in terms of rays.
3. It considers light as a ray.
4. It is discovered by Ibn al-Haytham.

A figure to represent ray optics:

Therefore, ray optics is valid when characteristic dimensions are much larger than the wavelength of light.

Hence, the correct option is (C).