Q10.17 (e) Answer the following questions:
Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification?
The typical size of the obstacle is much larger than the wavelength of light. Hence, the diffraction effect is negligibly small. Thus, the assumption that light travels in a straight line can be safely used in day-to-day life.