What will be the angular width of the central maxima in Fraunhofer diffraction when light of wavelength $6000 \,\mathring{A}$ is used and the slit width is $12 \times 10^{-5} \, \text{cm}$? (in $rad$)

What do the Fraunhofer lines in the solar spectrum indicate?

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. Fresnel's diffraction pattern occurs when the source of light or the screen on which the diffraction pattern is seen, or when both are at a finite distance from the aperture.
$B$. Diffracted light can be used to estimate the helical structure of nucleic acids.

$A$ plane wavefront of wavelength $6000 \, \mathring A$ is incident on a slit of width $0.2 \, mm$. $A$ Fraunhofer diffraction pattern is obtained on a screen at a distance of $2 \, m$ from the slit. What is the width of the central maximum in $mm$?

In Fraunhofer diffraction,draw the graph of the intensity of light on the screen versus the diffraction angle $\theta$ and write its characteristics.