Question

Consider sunlight incident on a slit of width 104 Å. The image seen through the slit shall(a) be a fine sharp slit white in colour at the centre(b) a bright slit white at the centre diffusing to zero intensities at the edges(c) a bright slit white at the centre diffusing to regions of different colours(d) only be a diffused slit white in colour

Answer 1

(a) be a fine sharp slit white in colour at the centre

Answer 2

Answer:

A) a fine sharp slit white in colour at the centre

Explanation:

Diffraction of light is described as the phenomenon of bending of light around the comers of an obstacle of the size of wavelength of light. The image seen through the slit will have a no diffraction phenomenon. This will be due to the large size of slit as compared to the wavelength.  

Width of the slit  - b = 104 Å = 104 x 10-10 m = 10-6 m = 1 pm

Wavelength of sunlight will vary from 4000 Å to 8000 Å.

Thus, the width of slit is comparable to that of the wavelength, so the diffraction occurs with maxima at centre. So, at the centre all colours will appear causing a fine sharp slit white in colour at the centre