If the source of light used in a Young's double slit experiment is changed from red to violet:

(2)

$\beta=\frac{\lambda \mathrm{D}}{\mathrm{d}}$

As $\lambda_{\mathrm{v}}<\lambda_{\mathrm{R}}$

$\Rightarrow \beta_{\mathrm{v}}<\beta_{\mathrm{R}}$

$\therefore$ Consecutive fringe line will come closer.

$\therefore(2)$