- #1
Pushoam
- 962
- 51
Homework Statement
Homework Equations
The Attempt at a Solution
When the system is in air
## d \sin {\theta} = n \lambda ## ...(1)
When the system is in water and slit separation is 2d,
## \mu 2d \sin {\theta} = n \lambda ## ...(2)
## \tan {\theta} = \frac y D ## ...( 3)
Taking d<<D, ## \tan {\theta} \approx \sin {\theta} ## ...(4)
## \frac { n \lambda }{ 2 \mu d} = \frac { y} D ## ...(5)
## y = \frac { n \lambda D }{ 2 \mu d} ## ...( 6)
Fringe width ## = \frac { \lambda D }{ 2 \mu d} ## ...(7)
Now, ## \frac { \lambda D}{ d} =s ## ...( 8)
Fringe width ## = \frac { s }{ 2 \mu } = \frac { 3s} 8 ##So, the correct option is (e).
Is this correct?