Chapter-10|Wave Optics|NCERT 12th Physics:
Young’s Double Slit Experiment:
The fringes pattern(dark and bright fringes) shows that light has wave nature and bright fringes are result of constructive interference of the two light waves and dark fringes result due to destructive interferences.
Let S₁ and S₂ are two very fine slits, at small distance d apart. From a strong source S, monochromatic light of wavelength λ are passing through S₁ and S₂. MN is a screen at a distance D from the slits.
Let a point p is at a distance y from O, the centre of screen.
For Constructive Interference(Bright Fringes):
For Destructive Interference(Dark Fringes):