Your voice bends round a doorway but a hillock returns an echo. The hillock is:
AToo far away to matter
BMuch larger than the wavelength
CSmaller than the wavelength
DMade of soft material
Answer & Solution
Correct answer: B. Much larger than the wavelength
1. Speech has a wavelength of about a metre.
2. A doorway is about that size, so sound bends round it.
3. A hillock is hundreds of metres, so most sound reflects.
_Source: NCERT Class 12 Physics Part II, Chapter 10, Wave Optics._
Related questions
Blue sky seen through a rotating polaroid rises and falls in brightness. Sky light is:Two polaroids are set crossed. The light passing through both is:Ordinary lamp light passes through one polaroid. Its intensity drops to:Wiggle a string up and down and a wave runs along it. The displacement is at right angles The rainbow of colours you see on a CD comes from:Diffraction is shown by:Near the edge of a shadow you see alternate dark and bright bands. This is:In Young's pattern, consecutive bright fringes are: