The condition for diffraction is

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

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

$A$ single slit of width $a$ is illuminated by a monochromatic light of wavelength $600 \, nm$. The value of $a$ for which the first minimum appears at $\theta = 30^{\circ}$ on the screen will be ........... $\mu m$.

The condition for observing Fraunhofer diffraction from a single slit is that the light wavefront incident on the slit should be

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