In Fraunhofer diffraction,light of wavelength $6328 \ \mathring{A}$ is incident perpendicularly on a slit of width $0.2 \ mm$. The angular width of the secondary maxima or minima will be: (in $^{\circ}$)

$A$ single slit Fraunhofer diffraction pattern is formed with white light. For what wavelength of light does the third secondary maximum in the diffraction pattern coincide with the second secondary maximum in the pattern for red light of wavelength $6500 Å$ (in $Å$)?

Explain that for a greater distance,the spreading due to diffraction dominates over that due to ray optics. $OR$ Explain the importance of Fresnel distance.

Fresnel diffraction is produced due to light rays falling on a small obstacle. The intensity of light at a point on a screen beyond an obstacle depends on

What do the Fraunhofer lines in the solar spectrum indicate?

Find the half-angular width of the central maximum in the Fraunhofer diffraction pattern produced by a slit of width $12 \times 10^{-5} \text{ cm}$,when illuminated by monochromatic light of wavelength $6000 \, \mathring{A}$. (Answer in degrees)