Question

Young's double slit experiment is made in a liquid. The 10^th bright fringe in the liquid lies where 6^th dark fringe lies in vacuum. The refractive index of liquid is –

• A. 1.8
• B. 1.54
• C. 1.67
• D. 1.2

Answer 1

Answer: (A)

1.8

Answer 2

b =$\frac{D\lambda}{d}$

\ 10b¢ = (5.5) b

10l¢ $\left( \frac{D}{d} \right)$ = 5.5$\frac{D\lambda}{d}$

\ $\frac{\lambda}{\lambda'}$= $\frac{10}{5.5}$= m

\ m = 1.8