$A$ screen is placed at $50 \ cm$ from a single slit,which is illuminated with light of wavelength $600 \ nm$. If the separation between the $1^{st}$ and $3^{rd}$ minima in the diffraction pattern is $3 \ mm$,then the slit width is: (in $mm$)

Describe the simplest experiments to observe a diffraction pattern.

$A$ slit of size $0.15 \ cm$ is placed at $2.1 \ m$ from a screen. On illuminating it by a light of wavelength $5 \times 10^{-5} \ cm$,the width of the central maxima will be:

Which of the following statements are correct with reference to single slit diffraction pattern?
$(I)$ The central maxima is twice as wide as the secondary maxima.
$(II)$ The intensity of secondary maxima decreases as we move away from the central maxima.
$(III)$ The width of the central maxima is independent of the slit width.
$(IV)$ The intensity of the central maxima is the same as that of the secondary maxima.

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 beam of monochromatic light of wavelength $5000 \mathring{A}$ is incident normally on a single narrow slit of width $0.001 \text{ mm}$. The light is focused by a convex lens on a screen placed on its focal plane. The first minima will be formed for the angle of diffraction of . . . . . . (degree).