AP EAMCET2003PhysicsWave Optics
In Young's double slit experiment, an interference pattern is obtained on a screen by a light of wavelength 6000 Ã… coming from the coherent sources S₁ and S₂ . At certain point P on the screen third dark fringe is formed. Then, the path difference S₁ P-S₂ P in microns is:
Options
- A0.75
- B1.5
- C3.0
- D4.5
Correct answer
B. 1.5
Step-by-step solution
=6000 Ã…=6 10⁻⁷ ~m Path difference for dark fringe; x=(2 n+1) / 2 For third dark fringe, n=2 x=(2 2+1) 6 10⁻⁷ 2 = 5 6 10⁻⁷ 2 =15 10⁻⁷=1.5 10⁻⁶ ~m =1.5 m