Different spectral lines of the Balmer tenet (transitions -2, with it being the principal quantum number) fall one at a ame on a Yomg's double slit apparans The separation between the shrs is df and the screen is placed at a constant distance from the slits What factor should d be mailuphed by to maintain a constant fringe width for vanous lines, as 71 takes different allowed values" 72 4n n + 4 4n 4n n - 4 4n n + 4