Fraunhoffer Diffraction

Consider Fraunhoffer diffraction pattern obtained with a single slit illuminated at normal incidence. At the angular position of the first diffraction minimum the phase difference (in radians) between the wavelets from the opposite edges of the slit is

A light of wavelength lambda is incident on an object of size b. If a screen is at a distance D from the object. Identify the correct condition for the observation of different phenomenon a) if b^(2)=D lambda , Fresnel diffraction is observed b) if b^(2)gtgtD lambda , Fraunhoffer diffeaction is observed c) b^(2)ltltD lambda , Fraunhoffer diffraction is observed d) b^(2)gtgtD almbad , the approximation of geometrical optics is applicable

Angular width of central maximum in the Fraunhoffer diffraction pattern of a slit is measured. The slit is illuminated by light of wavelength 6000Å . When the slit is illuminated by light of another wavelength, the angular width decreases by 30% . Calculate the wavelength of this light. The same decrease in the angular width of central maximum is obtained when the original apparatus is immersed in a liquid. Find the refractive index of the liquid.

If a single slit fraunhoffer diffraction set up is used with light of wavelength 4000Å . Distance D between central maximum and first minimum found to be 0.3 cm in set up if the wavelength changed to 6000Å the corresponding value of D will be

The centre of the diffraction pattern in Fraunhofer diffraction is always

For Fraunhofer diffraction to occur

The adjacent figure shows Fraunhoffer’s diffraction due to a single slit. If first minimum is obtained in the direction shown, then the path difference between rays 1 and 3 is

If light with wavelength 0.50 mm falls on a slit of width 10 mm and at angle theta=30^(@) to its normal. Then angular position of first minima located on any sides of the central Fraunhoffer's diffraction will be at :