Which of the following colourful patterns is due to the diffraction of light?

Light of wavelength $\lambda$ is incident on a slit of width $d$. The resulting diffraction pattern is observed on a screen at a distance $D$. The linear width of the principal maximum is then equal to the width of the slit if $D$ equals

In a single slit diffraction experiment,for a wavelength of light $\lambda$,the half-angular width of the central maxima is $\theta$. For a wavelength of light $p\lambda$,the half-angular width of the central maxima is $q\theta$. What is the ratio of the half-angular widths of the first secondary maxima in the first case to the second case?

The phenomenon of diffraction can be exhibited by

The luminous border that surrounds the profile of a mountain just before the sun rises behind it is an example of:

Light of wavelength $6000 \, \mathring{A}$ is incident on a single slit of width $0.3 \, mm$. The angular position of the first minima will be