Question 409: Wave Optics

Question

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that 8
th
bright fringe in the medium lies where 5
th
dark fringe lies in air. The refractive index of the medium is nearly

Accepted Answer

Position of 8
th
bright fringe in medium
x = $${{8{\lambda _m}D} \over {\mu d}}$$
Position of 5
th
dark fringe in air,
x' = $${{\left( {5 - {1 \over 2}} \right){\lambda _{air}}D} \over d}$$ = $${{4.5{\lambda _{air}}D} \over d}$$
According to question
$${{8{\lambda _m}D} \over {\mu d}}$$ = $${{4.5{\lambda _{air}}D} \over d}$$
$$ \Rightarrow $$ $$\mu $$ = 1.78

Answer

1.59

Answer

1.69

Answer

1.78

Answer

1.25

Wave Optics

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that 8 th bright fringe in the medium lies where 5 th dark fringe lies in air. The refractive index of the medium is nearly

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