JEE Main20202 Sep 2020Morning ShiftPhysicsWave OpticsActual
Interference fringes are observed on a screen by illuminating two thin slits 1 mm apart with a light source λ = 632 . 8 nm . The distance between the screen and the slits is 100 cm . If a bright fringe is observed on a screen at distance of 1 . 27 mm from the central bright fringe, then the path difference between the waves, which are reaching this point from the slits is close to :
Options
- A1 . 27 μ m
- B2   . 87 nm
- C2   nm
- D2 . 05   μm
Correct answer
A. 1 . 27 μ m
Step-by-step solution
Δ P = d sin θ = d θ = d y D = 10 - 3 × 1 . 270   mm 1   m = 1 . 27 μ m 1 . 27 μ m