Question
If one of the slits of a standard Young’s double slit experiment is covered by a thin parallel sided glass slab so that it transmits only one half the light intensity of the other, then -
A.
the fringe pattern will get shifted towards the covered slit
B.
the fringe pattern will get shifted away from the covered slit
C.
the bright fringes will become more bright and the dark ones will become less bright
D.
the fringe width will changed
Answer :
the fringe pattern will get shifted towards the covered slit
Solution :
$$\eqalign{
& {I_{\max }} = {\left( {\sqrt {{I_1}} + \sqrt {{I_2}} } \right)^2} = {\left( {\sqrt {{I_1}} + \sqrt {\frac{I}{2}} } \right)^2} < 4I \cr
& {I_{\min }} = {\left( {\sqrt {{I_1}} - \sqrt {\frac{I}{2}} } \right)^2} > 0 \cr} $$