A monochromatic beam of light falls on YDSE apparatus at some angle (say θ) as shown in figure. A thin sheet of glass is inserted in front of the lower slit S2. The central bright fringe (path difference = 0) will be obtained
Answer & explanation
Correct answer: option 4
If dsinθ = (µ −1)t, central fringe is obtained at O
If dsinθ > (µ −1)t, central fringe is obtained above O and
If dsinθ < (µ −1)t, central fringe is obtained below O.