Q10.17 (d) Answer the following questions:

Two students are separated by a 7 m partition wall in a room 10 m high. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily.

Answers (1)
P Pankaj Sanodiya

The size of obstacle should be comparable to the wavelength for diffraction of waves by obstacles, through a large scale.

This comes from

sin\theta =\frac{\lambda}{a}

sin\theta =\frac{10^{-7}}{10}=10^{-8}

This implies \theta\rightarrow 0

it means the light goes almost unbent and hence student are unable to see each other.