In a single slit diffraction pattern, the distance between the plane of the slit and the screen is $1.4 \text{ m}$. The width of the slit is $0.66 \text{ mm}$. The second maximum is formed at the distance of $2.8 \text{ mm}$ from the center of the screen. The wavelength of light used is (in $\text{ Å}$)

$A$ 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 ........ $mm$.

Sodium light of wavelengths $650\, nm$ and $655\, nm$ is used to study diffraction at a single slit of aperture $0.5\, mm$. The distance between the slit and the screen is $2.0\, m$. The separation between the positions of the first maxima of the diffraction pattern obtained in the two cases is $x \times 10^{-5}\, m$. Find the value of $x$.

$A$ plane wavefront of wavelength $\lambda$ is incident on a slit of width $a$. The angular width of the principal maximum is

$A$ parallel monochromatic beam of light is incident normally on a narrow slit. $A$ diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first maximum of the diffraction pattern,the phase difference between the rays coming from the edges of the slit is

$A$ screen is placed at a distance $50\,cm$ from a single slit,which is illuminated with light of wavelength $690\,nm$. If the distance between the first and third minima is $3.00\,mm$,what is the width of the slit (in $,mm$)?