In Young's double slit experiment, 10th maximum is observed at a certain point on the screen when light of wavelength 700 nm illuminates the slits. The order of maximum observed at the same point, if light of wavelength 500 nm is used, will be
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 14
At a fixed point on the screen the path difference is fixed. A bright fringe of order n forms where the path difference is \( n\lambda \).
\( \displaystyle x = \frac{n\lambda D}{d} \)
For the same point (same x, D, d):
\( \displaystyle n_1\lambda_1 = n_2\lambda_2 \)
\( \displaystyle n_2 = \frac{10 \times 700\,\mathrm{nm}}{500\,\mathrm{nm}} = 14 \)