Answer & explanation
Correct answer: option 3
$\text{Fringe Width }\beta = \frac{\lambda D}{d}$
$ \lambda = \frac{\lambda_0}{\mu}$
$\Rightarrow \lambda \text{will decrease in water}$
Correct answer: option 3
$\text{Fringe Width }\beta = \frac{\lambda D}{d}$
$ \lambda = \frac{\lambda_0}{\mu}$
$\Rightarrow \lambda \text{will decrease in water}$