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

$A$ slit of width $d$ is illuminated by white light. The first minimum for red light $(\lambda = 6500\,\mathring{A})$ will fall at $\theta = 30^\circ$ when $d$ will be

$A$ diffraction pattern is obtained by making blue light incident on a narrow slit. If blue light is replaced by red light,then:

In a diffraction experiment from a single slit,the angular width of the central maximum does $NOT$ depend upon:

The angular deviation of the $5^{th}$ order dark fringe is $12^{\circ}$ in a single slit experiment. If the width of the slit is $9 \mu m$, then the wavelength of the incident light is: (in $Å$)

$A$ 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 secondary maximum of the diffraction pattern,the phase difference between the rays coming from the edges of the slit is