The width of the $nth$ $HPZ$ (Half Period Zone) will be:

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

$A$ Fraunhofer diffraction pattern due to a single slit of width $0.3 \text{ mm}$ is obtained on a screen placed at a distance of $3 \text{ m}$ from the slit. The first minima lie at $5.5 \text{ mm}$ on either side of the central maximum on the screen. The wavelength of light used is (in $\text{ Å}$)

To observe diffraction,the size of an obstacle:

$A$ screen is placed $50 \, cm$ from a single slit which is illuminated with $6000 \, \mathring{A}$. If the distance between the first and third minima in the diffraction pattern is $3 \, mm$,what is the width of the slit?

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