Optics Question 168

Question: Angular width of central maxima in the Fraunhoffer diffraction pattern of a slit is measured. The slit is illuminated by light of wavelength 6000AA . When the slit is illuminated by light of another wavelength, the angular width decreases by 30%. The wavelength of this light will be

Options:

A) 6000AA

B) 4200AA

C) 3000AA

D) 1800AA

Show Answer

Answer:

Correct Answer: B

Solution:

Angular width β

=2λd

β1β2=λ1λ2β70100β=6000λ2λ2=4200AA



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