1. Light passing through a double-slit arrangement is viewed on a distant screen. The interference pattern observed on the screen would have the widest spaced fringes for the case of
(a) Red light and a small slit spacing.
(b) Blue light and a small slit spacing.
(c) Red light and a large slit spacing.
(d) Blue light and a large slit spacing.
2. Light from a green laser of wavelength 530 nm passes through two slits that are 400 nm apart. The resulting pattern formed on a screen in front of the slits is shown in Fig. 24-55. If point A is the same distance from both slits, how much closer is point B to one slit than to the other?
(a) 530 nm.
(b) 265 nm.
(c) 400 nm.
(d) 0 nm.
(e) It depends on the distance to the screen.

A