Which of the following waves exhibits clear diffraction?

Assertion: $A$ coloured spectrum is seen when we look through a muslin cloth.
Reason: It is due to the diffraction of white light on passing through fine slits.

$A$ plane wave front of wavelength $\lambda$ is incident on a single slit of width $b$. What is the angular width of the secondary maximum?

In a single slit diffraction of light of wavelength $\lambda$ by a slit of width $e$,the size of the central maximum on a screen at a distance $b$ is

The phenomenon that explains why light waves do not travel in a straight line is known as .......

$A$ single slit of width $0.1\, mm$ is illuminated by a parallel beam of light of wavelength $6000\, \mathring{A}$ and diffraction bands are observed on a screen $0.5\, m$ from the slit. The distance of the third dark band from the central bright band is ........ $mm$.