Light and sound both have wave character, yet diffraction is relatively more difficult to observe in light than sound because
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → its wavelength is very small
Diffraction is noticeable only when the size of the obstacle or aperture is comparable to the wavelength. The wavelength of visible light is about \( 4\times10^{-7} \) to \( 7\times10^{-7}\,\mathrm{m} \), while audible sound has wavelengths from a few cm to several metres, the size of doors and walls. So sound bends round everyday objects, but light needs very narrow slits to show diffraction.
Why the other options are incorrect
Option (1) it can travel in vacuum — Incorrect. Travelling through vacuum has nothing to do with bending round obstacles.
Option (3) it is transverse in nature — Incorrect. Longitudinal and transverse waves diffract alike; the nature of vibration decides polarisation, not diffraction.
Option (4) its speed is very large — Incorrect. Speed alone does not decide diffraction; what matters is the wavelength, \( \lambda = v/\nu \).
NCERT (2026-27):
Diffraction – “… Diffraction is a general characteristic exhibited by all types of waves, be it sound waves, light waves, water waves or matter waves. Since the wavelength of light is much smaller than the dimensions of most obstacles; we do not encounter diffraction effects of light in everyday observations.”