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=‌The position of the second bright fringe is:
y2=‌The separation between the first and second order bright fringes is:
y2−y1=‌−‌=‌From this, we can derive the formula for the wavelength
λ as:
λ=‌Substituting the given values into this equation:
λ=‌| 0.553×10−3×2.08×10−3 |
| 1.8 |
Solving this gives:
λ=639×10−9mTherefore, the wavelength of the light used is:
λ=639‌nm