Question

Consider sunlight incident on a slit of width 10⁴ Å. Get 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 a the centre diffusing to regions of different colours
• D. Only be a diffused slit white in colour

Answer 1

Answer: (A)

Be a fine sharp slit white in colour at the centre

Answer 2

Visible range $\lambda = 3900Åto7000Å$

Given width of the slit, $a = 10^{4}Å = 10000Å$

Thus $a > \lambda$hence no diffraction occurs. The image seen through the slit shall be a fine sharp slit white in colour at the centre.