Question

In YDSE, let A and B be two slits. Films of thicknesses tA and tB and refractive indices μA and μB are placed in front of A and B, respectively. If μAtA=μBtB, then the central maxima will :

A. Not shift
B. Shift toward A
C. Shift toward B
D. (b) if tB>tA and (c) if tB

Answer 1

In YDSE with films introducing equal optical path lengths in front of slits A and B, the central maxima will not shift because the phase difference remains unchanged.

The correct option is (b) if tB > tA and part (c) if μB is larger than μA or vice versa

Step-by-step explanation:

In the Young's Double-Slit Experiment (YDSE), when films of different thicknesses (tA and tB) and refractive indices (μA and μB) are introduced in front of slits A and B respectively, and if μAtA equals μBtB, the optical path length that the light travels through each film remains the same. This means that the overall phase difference introduced by the films to the light from the respective slits is the same and hence, the central maxima will not shift.

Therefore, the correct option is (b) if tB > tA and part (c) if μB is larger than μA or vice versa, the central maxima still will not shift because the product of thickness and refractive index for both films is equal.