Q83 / 90 · JEE Main 2022 (27 Jun Shift 1) · Physics
In Young's double slit experiment the two slits are distance apart. Interference pattern is observed on a screen at a distance from the slits. The first dark fringe is observed on the screen directly opposite to one of the slits. The wavelength of light will be _____ .
Correct answer: 450
Solution
According to the question, the first dark fringe is observed directly opposite to one of the slits. Therefore, half of the fringe width is equal to half of the distance between the slits.
Hence, the correct answer is 450.