question_answer

Using monochromatic light of wavelength \[\lambda ,\] an experimentalist sets up the Young’s double slit experiment in three ways as shown.

If she observes that \[y=\beta ',\] the wavelength of light used is:                  [JEE ONLINE 09-04-2014]

A) 520 nm

B) 540 nm

C) 560 nm

D) 580 nm

Correct Answer: B

Solution :

[b] Given

n = 2 (from figure)

Applying formula

or,