In a Fraunhofer's diffraction obtained by a single slit aperture,the value of path difference for $n^{th}$ order of minima is

The angular width of the central maximum in a single-slit diffraction pattern does not depend on .........

$A$ narrow slit of width $2 \, mm$ is illuminated by monochromatic light of wavelength $500 \, nm$. The distance between the first minima on either side on a screen at a distance of $1 \, m$ is ........ $mm$.

Through a narrow slit of width $2 \,mm$, a diffraction pattern is formed on a screen kept at a distance $2 \,m$ from the slit. The wavelength of the light used is $6330 \mathring{A}$ and it falls normal to the slit and screen. Then, the distance between the two minima on either side of the central maximum is (in $\,mm$)

$A$ slit of width $a$ is illuminated by monochromatic light of wavelength $650 \ nm$. The value of $a$ when the first maximum is formed at a diffraction angle of $30^\circ$ is:

For Bragg's diffraction by a crystal to occur,the $X$-ray of wavelength $\lambda$ and interatomic distance $d$ must satisfy which condition?