In the figure, two isotropic point sources $S_1$ and $S_2$ emit light in phase at wavelength $\mathrm{\lambda }$ and at the same amplitude. The sources are separated by distance, $2d=6.00\mathrm{\lambda }$. They lie on an axis which is parallel to the $x$-axis which runs along a viewing screen at distance $D=20.0\mathrm{\lambda }$. The origin lies on the perpendicular bisector between the sources. The figure shows two rays reaching point $P$ on the screen at position $x_{\mathrm{P}}$. (a) At what value of $x_{\mathrm{P}}$ do the rays have the minimum possible phase difference? (b) What multiple of $\mathrm{\lambda }$ gives the minimum phase difference? (c) At what value of $x_{\mathrm{P}}$ do the rays have the maximum possible phase difference? What multiple of $\mathrm{\lambda }$ gives (d) that maximum phase difference and (e) the phase difference when $x_{\mathrm{P}}=6.50\mathrm{\lambda }$? (f) When $x_{\mathrm{P}}=6.50\mathrm{\lambda }$, is the resulting intensity at point $P$ a maximum, a minimum, an intermediate but closer to maximum, or an intermediate but closer to minimum?

If mirror $M_2$ in a Michelson interferometer is moved through $0.233 \mathrm{mm}$, a shift of $1,110$ bright fringes occurs. What is the wavelength of the light producing the fringe pattern?

Suppose that two waves have wavelength, $\mathrm{\lambda }=610 \mathrm{nm}$ in air. What multiple of $\mathrm{\lambda }$ gives their phase difference when they emerge if (a) $n_1=1.50, n_2=1.60$ and $L=7.00 \mathrm{\mu m}$ (b) $n_1=1.62, n_2=1.72$ and $L=7.00 \mathrm{\mu m}$ and (c) $n_1=1.83,$ $n_2=1.59$ and $L=2.16 \mathrm{\mu m}$?
(d) Suppose that in each of these three situations, the waves arrive at a common point (with the same amplitude) after emerging. Rank the situations according to the brightness the waves produce at the common point.

Monochromatic green light of wavelength $550 \mathrm{nm}$ illuminates two parallel narrow slits which are $5.60 \mathrm{\mu m}$ apart. Calculate the angular deviation $\mathrm{\theta }$ of the third-order $(m=3)$ bright fringe (a) in radians and (b) in degrees.

How much faster, in meters per second, does light travel in water than in diamond? See the table.

For a wavelength of 589 nm (yellow sodium light)

STP means '' standard temperature (0°C) and pressure (1 atm).''