Question

1. a. Light of wavelength 694.3 nm from a ruby laser is incident on two narrow parallel slits cut in a thin sheet of metal. The slits are separated by a distance of 0.088 mm. A screen is placed 1.5 m beyond the slits. Find the intensity, relative to the central maximum, at a point on the screen 1.4 cm to one side of the central maximum.

b. In a double-slit experiment, the intensity at the peak of the central maximum is I_max. What is the intensity when the path difference to a point on the screen is λ/1?

c. A 0.9-kHz sound wave is normally incident on two narrow windows, separated by 2 m. If a listener is standing 4.2 m beyond the windows on the midline, how far must she move laterally to be standing at the first interference minimum? Take the speed of sound to be 340 m/s.

d. Sodium light with wavelength 552.20 nm and 589.59 nm is incident on a grating with 6218 lines per centimeter. A screen is placed 3.1 m beyond the grating. What is the distance between the two spectral lines in the first-order spectrum on the screen? What is the distance between the two spectral lines in the second-order spectrum?

Answer 1