Light is reflecting off a wedge-shaped thin piece of glass producing bright and dark interference fringes.If a certain location has a bright fringe,a nearby point will have a dark fringe if the thickness of the glass increases by:

Question

Quizplus · Accepted Answer

The phase difference between the two interfering beams at adjacent bright and dark fringes is π radians or half a wavelength. Thus, the path difference between them is λ/2, which is equal to the thickness of the wedge-shaped glass. To move from a bright fringe to a nearby dark fringe, the path difference needs to increase by another half-wavelength or λ/2. Therefore, the thickness of the glass needs to increase by λ/4, which is the same as option B.

Light Is Reflecting Off a Wedge-Shaped Thin Piece of Glass