Wave Optics - Concept's in Fringe Width

Description:

It is defined as the distance between two successive maxima or minima.

Observations based on the formula of Fringe width -

• If distance (D) of screen is increased, the width of fringe will increase. If the distance (D) of screen is decreased, the width of fringe will decrease.

• If distance (d) between slits is increased, the width will decrease.

  If the slits are very far from each other, then we will not be able to differentiate between the fringes (but fringes will be present) and we will see general brightness.

• If distance (d) between slits is decreased, the width will increase.

  If both the slits merge, then we will no longer see fringes; instead we will see general brightness.

• The value of λ varies for different color lights, so if a color light have higher value of λ, then the width of fringes will be large and vice-versa.

  Young’s experiment does not work for White light, as it is a combination of various lights, each of which has a different value of λ.