Question

In the previous question, films of thicknesses tA and tB and refractive indices μA and μB, are placed in front of A and B respectively. If μAtA = μBtB, the central maximum will

(a) not shift

(b) shift towards A

(c) shift towards B

(d) option (b), if tB > tA; option (c), if tB < tA

Answer 1

Correct Answer is: (d) option (b), if tB > tA; option (c), if tB < tA

Additional path difference due to the two films

= (μB - 1) tB - (μA - 1) tA = tA - tB.