Question

Passage # 4 (Q.42 to 44)
In Young's experiment, light of wavelength 6000A is incident on the double slits. Intensity of central
maximum, formed at O is lo, and the angular fringe-width is 0.1°. If a thin transparent plate 'A' is placed in
the path of one of the interfering beams, it is found that smallest thickness of the plate, for which intensity at
Obecomes half of maximum, is 250 nm. Also, the zero order fringe earlier at O now forms 0.5 mm from 0.
However, instead of plate 'A', if a plate 'B' made of another material is placed in the path of one of the
interfering beams, smallest thickness of B for which intensity at O becomes zero is 300 nm. Neglect
absorption of light by the plate. Answer the following questions :
S
d
0
D
D>>>d
Q.42
Refractive index of plate 'A' is
(A) 1.4
(B) 1.5
Refractive index of plate 'B' is
(A) 2
(B) 1.8
(C) 1.6
Q.43
(D) 1.82
(C) 1.65
(D) 1.48
Distance of screen from the double slits is
(A) 1.1 m
(B) 1.4 m
(C) 0.8 m
(D) 1.5 m​

Answer 1

Answer:

c) 1.6 ✔........................