In YSDE, both slits are covered by transparent slab. Upper slit is covered by slab of R.I. 1.5 and thickness t and lower is
covered by R.I. `4/ 3` and thickness 2t, then central maxima
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Options

A. shifts in +ve y-axis direction
B. shifts in -ve y-axis direction
C. remains at same position
D. may shift in upward or downward depending upon wavelength of light

Answer

B

Explanation

`Deltax_(1)=(mu_(1)-1)t=(1.5-1)t=0.5t`
and `Deltax_(2)=(mu_(2)-1)xx2t=(4/3-1)xx2t=2/3t`.
As `Deltax_(2)gtDeltax_(1)`, so shift will be along -ve y-axis.