1.

In YDSE the screen is aat a distance D from the plane of the slits and slits are illuminated by plane monochromatic light of wavelength lambda. P is a point on the screen at a distance y from the central maximum. If by some special arrangement the slits be moved symmetrically apart with relative volocity v, estimate the number of fringes crossing the point p per unit time.

Answer»

Solution :Let 1= distance between the slits
`V= (d1)/(DT)" path diff "x=(y1)/(D)""(dx)/(dt)=(y)/(D)*(d1)/(dt)=(YV)/(D)`
Since a change in optical path difference of `lambda` corresponds to one fringe, so the number of FRINGES crossing point P PER unit time is `(dx)/(dt)(1)/(lambda)= (yv)/(D)`.


Discussion

No Comment Found

Related InterviewSolutions