A transparent paper (refractive index = 1.45) of thickness 0-02 mm is pasted on one of the slits of a Young's double slit experiment which uses monochromatic light of wavelength 620 nm. How many fringes will cross through the centre if the paper is removed ?

Answer

`14.5`

Explanation

From `y_(0) = (beta)/(lambda)(mu - 1)`
No. of fringes that cross when paper is removed
`= (y_(0))/(beta) = ((mu - 1)t)/(lambda) = ((1.45 - 1) xx 0.02 xx 10^(-3))/(620 xx 10^(-9))`
`= 14.5`