In YDSE, monochromatic light falls on a screen 1.80 m from two slits separated by 2.08 mm . The first and second order bright fringes are separated by 0.553 mm . The wavelength of light used is
In the Young's Double Slit Experiment (YDSE), for monochromatic light shining on a screen 1.80 m away from two slits separated by 2.08 mm , the separation of the first and second order bright fringes is 0.553 mm . To find the wavelength of light used, we use the following calculations: The position of the first bright fringe is given by: y1=‌
λD
d
The position of the second bright fringe is: y2=‌
2λD
d
The separation between the first and second order bright fringes is: y2−y1=‌
2λD
d
−‌
λD
d
=‌
λD
d
From this, we can derive the formula for the wavelength λ as: λ=‌
(y2−y1)d
D
Substituting the given values into this equation: λ=‌
0.553×10−3×2.08×10−3
1.8
Solving this gives: λ=639×10−9m Therefore, the wavelength of the light used is: λ=639‌nm