True-false questions are worth 2 points each, three-choice multiple choice questions are worth 3 points each, five-choice multiple choice questions are worth 6 points each. The maximum possible score is 96. The exam period was 90 minutes; the mean was 78.3; the median was 81. Click here to see page1 page2 page3 of the formula sheet that came with the exam.

Some helpful information: • A reminder about prefixes: p (pico) = 10^{-12}; n (nano) = 10^{-9}; μ (micro) = 10^{-6}; m (milli) = 10^{-3}; k (kilo) = 10^{+3}; M or Meg (mega) = 10^{+6}; G or Gig (giga) = 10^{+9}.

A ray of red light passes through a prism. The trajectory is such that the ray is horizontal when inside the prism. The index of refraction n of the prism is 1.517 at the wavelength of red light.

At what angle α does the ray enter the prism?

(a) 0° (b) 19° (c) 30° (d) 49° (e) 60°

(a) β < α (b) β = α (c) β > α

(a) below the ray of red light. (b) at the same trajectory as the ray of red light. (c) higher than the ray of red light.

(a) 1.15 (b) 1.5 (c) 1.75 (d) 2 (e) 2.5

A woman is staring at the back (the convex side) of a spoon, at a distance much larger than the spoon's radius of curvature. The image of the woman's face is:

(a) reduced, real, inverted (b) reduced, virtual, upright (c) magnified, real, upright

What is the maximum height y above the floor the mirror can be placed, so that the man can still see his shoes in the mirror?

(a) 0 cm (b) 13.5 cm (c) 45 cm (d) 85 cm (e) 100 cm

A lady bug of height 0.5 cm is placed 5 cm away from a converging lens. The focal distance of the lens is 12 cm.

At what distance from the lady bug will its image appear?

(a) 7.6 cm left of the lady bug (b) 3.6 cm to the left of the lady bug (c) 5 cm to the right of the lady bug (d) 7.6 cm to the right of the lady bug (e) at infinity

(a) 0.05 cm (b) 0.5 cm (c) 0.86 cm

(a) upright (b) inverted

(a) real (b) virtual

An object is placed 20 cm to the left of a 2-lens system of convex lenses. The left lens has a focal length f_{1 }= 12 cm. The right lens has a focal length f_{2 }= 18 cm. The lenses are 40 cm apart.

Where is the final image located?

(a) 30 cm right of lens #1 (b) 22.5 cm left of lens #2 (c) 22.5 cm right of lens #1 (d) 15 cm right of lens #2 (e) at infinity

(a) -3.38 (b) -2.25 (c) -1.5 (d) 2.25 (e) 3.38

Initially unpolarized light is incident on a series of two linear polarizers.

If the initial intensity of the incident (unpolarized) light is I_{0}, what is the intensity I_{2} transmitted by the stack?

(a) I_{2} = 0.015 I_{0} (b) I_{2} = 0.0301 I_{0} (c) I_{2} = 0.48 I_{0}

(a) B_{2} = 0.0251 B_{1} (b) B_{2} = 0.1736 B_{1} (c) B_{2} = B_{1}

Electromagnetic waves of frequency 4 × 10^{6} Hz and average energy density 1.5 × 10^{-6} J/m^{3} traveling in a vacuum are incident upon a panel of area 12 m^{2}.

What is the wavelength of these waves?

(a) 1.33 × 10^{-2} m (b) 75 m (c) 1.2 × 10^{15} m

(a) 5.4 × 10^{3} J (b) 8.1 × 10^{4} J (c) 3.2 × 10^{5} J

(a) faster than (b) at the same speed as (c) slower than

(a) A (from n=1.3 to n=1.4) (b) B (from n=1.4 to n=1.2)

A film of oil of thickness t is floating on water. The index of refraction is 1.0, 1.45 and 1.33 for air, oil and water, respectively. A person views the film from the air in a direction normal to the surface.

The person sees that there is constructive interference of reflected light of wavelength 630 nm. What is the minimum thickness t of the oil film?

(a) 109 nm (b) 218 nm (c) 436 nm

(a) 155 nm (b) 225 nm (c) 310 nm

(a) 4,470 m (b) 5,500 m (c) 12,600 m

For a wavelength of 440 nm, a diffraction grating produces a 2nd-order bright fringe at an angle of 28°.

What is the slit spacing of the grating?

(a) 937 nm (b) 1,870 nm (c) 3,749 nm

(a) 308 nm (b) 314 nm (c) 627 nm

A double-slit experiment is set up using red light with a wavelength of 633 nm. The slits are separated by a distance of 0.075 mm. The interference pattern is viewed on a screen 1.8 m away from the slits.

What is the distance between two adjacent bright fringes on the screen?

(a) 1.52 cm (b) 1.69 cm (c) 3.04 cm

(a) 633 nm (b) 950 nm (c) 1899 nm

(a) 1.5 cm (b) 1.7 cm (c) 3.0 cm