Question 413: Waves Optics

Question

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

Waves Optics

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

Choose the correct answer: