Fraunhofer Diffraction Due to a Single Slit

Describe briefly how a diffraction pattern is obtained on a screen due to a single narrow slit illuminated by a monochromatic source of light. Hence obtain the conditions for the angular width of secondary maxima and secondary minima.

For a single slit of width "a", the first minimum of the interference pattern of a monochromatic light of wavelength λ occurs at an angle of λa. At the same angle of λa, we get a maximum for two narrow slits separated by a distance "a". Explain.

Show graphically the intensity distribution in Fraunhofer's single slit diffraction experiment. Label the axes.

In Fraunhofer diffraction, how is the angular width of the central bright fringe affected when slit separation is increased?

Explain two types of diffraction of light.

Draw the intensity distribution for the diffraction bands produced due to single slit ?

Two wavelengths of sodium light of 590 nm and 596 nm are used in turn to study the diffraction taking place at a single slit of aperture 2 × 10⁻⁶ m. The distance between the slit and the screen is 1·5 m. Calculate the separation between the positions of first maxima of the diffraction pattern obtained in the two cases.

A point is situated at 7cm and 7·2 cm from two coherent sources. Find the· nature of illumination at the point if wavelength of light is 4000A.