JEE Advanced2016PhysicsWave OpticsActual
While conducting the Young's double slit experiment, a student replaced the two slits with a large opaque plate in the x-y plane containing two small holes that act as two coherent point sources S 1 , S 2 emitting light of wavelength 600 nm. The student mistakenly placed the screen parallel to the x-z plane (for z > 0) at a distance D = 3m from the mid-point of S 1 , S 2 , as shown schematically in the figure. The di
Options
- AHyperbolic bright and dark bands with foci symmetrically placed about O in the x-direction
- BSemi circular bright and dark bands centered at point O
- CThe region very close to the point O will be dark
- DStraight bright and dark bands parallel to the x-axis
Correct answer
B. Semi circular bright and dark bands centered at point O
Step-by-step solution
Path difference at point O = d = .6003 mm = 600300 nm = 2001 2 600 n m = 1000 λ + λ 2 ⇒ minima form at point O Line S 1 S 2 and screen are ⊥ to each other so fringe pattern is circular (semi-circular because only half of screen is available)