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

If a narrow slit of width $2 \, mm$ is illuminated by monochromatic light of wavelength $500 \, nm$,then the distance between the first minima on both sides on a screen at a distance of $1 \, m$ is ....... $mm$.

In a single slit diffraction, the slit is illuminated with light of wavelength $6000 \text{ Å}$. If the slit were illuminated by a light of wavelength $\lambda$ the angular width of the central maximum decreases by $30 \%$. Then $\lambda$ is (in $\text{ Å}$)

In a Fraunhofer diffraction due to a single slit,the diffraction pattern is formed on the focal plane of a lens of focal length $f = 1 \ m$. The width of the slit is $a = 0.3 \ mm$. If the third minimum is formed at a distance of $5 \ mm$ from the central maximum,find the wavelength of light in $\mathring{A}$.

Light of wavelength $589.3 \, nm$ is incident normally on a slit of width $0.1 \, mm$. What will be the angular width of the central diffraction maximum in degrees?

$A$ parallel beam of fast-moving electrons is incident normally on a narrow slit. $A$ screen is placed at a large distance from the slit. If the speed of the electrons is increased,which of the following statements is $CORRECT$?