Please answer all questions.

1			A double-slit experiment is done in the usual way with 480-nm light and narrow slits that are 0.050 cm apart. At what angle to the straight-through beam will one observe (a) the third-order bright spot and (b) the second minimum from the central maximum?
			A)	(a) 0.17° (b) 0.083°
			B)	(a) 0.0017° (b) 0.00083°
			C)	(a) 0.055° (b) 0.110°
			D)	(a) 2.88° (b) 0.170°
2			Red light of wavelength 644 nm, from a point source, passes through two parallel and narrow slits which are 1.00 mm apart. Determine the distance between the central bright fringe and the third dark interference fringe formed on a screen parallel to the plane of the slits and 1.00 m away.
			A)	1.61 mm
			B)	1.93 mm
			C)	1.61 µm
			D)	2.25 mm
3			Two flat glass plates are pressed together at the top edge and separated at the bottom edge by a strip of tinfoil. The air wedge is examined in yellow sodium light (589 nm) reflected normally from its two surfaces. A dark interference fringe is observed at both the top and bottom edges. Including these, a total of 42 dark interference fringes are observed from top to bottom. Compute the thickness of the tinfoil.
			A)	12.07 µm
			B)	12.37 µm
			C)	24.14 µm
			D)	12.07 mm
4			A single slit of width 0.140 mm is illuminated by monochromatic light, and diffraction bands are observed on a screen 2.00 m away. If the second dark band is 16.0 mm from the central bright band, what is the wavelength of the light?
			A)	560 nm
			B)	5600 nm
			C)	560 µm
			D)	1.12 µm
5			Green light of wavelength 500 nm is incident normally on a diffraction grating, and the second-order maximum is observed to be 32.0° from the normal. How many lines/cm are marked on the grating?
			A)	5.30 × 103 lines/cm
			B)	1.89 × 10-6 lines/cm
			C)	5.30 × 105 lines/cm
			D)	1.06 × 104 lines/cm
6			A narrow beam of yellow light of wavelength 600 nm is incident normally on a diffraction grating ruled 2000 lines/cm, and images are formed on a screen parallel to the grating and 1.00 m distant. Compute the distance along the screen from the central bright line to the first-order lines.
			A)	12.1 cm
			B)	12.0 cm
			C)	0.120 cm
			D)	0.121 cm
7			Determine the ratio of the wavelengths of two spectral lines if the second-order maximum of one line coincides with the third-order maximum of the other, both lines being examined by means of the same grating.
			A)	9:4
			B)	6:1
			C)	3:2
			D)	6:3
8			A spectrum of the Sun's radiation in the infrared region is produced by a diffraction grating. What is the wavelength being studied if the first order maximum occurs at an angle of 25.0° with the normal, while the fourth-order maximum of the hydrogen line of wavelength 656.3 nm occurs at 30.0°?
			A)	5.55 × 10-7 m
			B)	2.22 × 10-6 m
			C)	3.11 × 10-6 m
			D)	1.39 × 10-7 m
9			Which of the following effects could not be observed for sound waves in air?
			A)	interference
			B)	refraction
			C)	polarization
			D)	diffraction
10			A thin slit produces a fuzzy shadow because of
			A)	refraction
			B)	diffraction
			C)	polarization
			D)	condensation