Physics 202 MWF 10:20 Spring 1996 (Ford)
Exam IV Chapts. 36-39 in SZY College Physics 7e


Show all your work. Partial credit will be given if earned. Write your answers in the blanks provided.


(14 pts) 1. A ray of light traveling in water is incident on a water-glass interface as shown. The angle of incidence is 37° and the angle of refraction is 30°.

a) If the index of refraction of water is n = 1.33, what is the index of refraction of the glass?

Ans. ________________

b) If the wavelength of the light in the glass is 400 nm, what is its wavelength in the water?

Ans. ______________


(12 pts) 2. Unpolarized light with intensity I₀ is traveling in the +z-direction. It is passed through two polarizers, that have their polarizing axes oriented as shown in the sketch. (The axis of the first polarizer that the light passes through is oriented at 37° from the y-axis, and the axis of the second polarizer is aligned along the x-axis.) In terms of I₀, what is the intensity of the light passed by each polarizer?

Ans. polarizer #1 _________________

polarizer #2 ________________


(18 pts) 3.
a) Monochromatic coherent light from a distant source is incident on a single slit 0.800 mm wide. On a screen 3.00 m from the slit, the distance from the center of the central maximum of the diffraction pattern to the first minimum is 1.25 mm. What is the wavelength of the light?

Ans. ______________

b) Monochromatic coherent light from a distant source is incident on a pair of very narrow slits that are separated by 0.600 mm. In the resulting interference pattern of a screen 2.50 m away, adjacent bright fringes are separated by 3.20 mm. What is the wavelength of the light?

Ans. _________________


(18 pts) 4. An object 4.0 cm tall is to the left of a converging lens that has a focal length of 9.0 cm. The image is 0.5 cm tall and is inverted.

a) How far is the object from the lens?

Ans. _____________

b) How far is the image from the lens?

Ans. _________________

c) Is the image real or virtual?

Ans. _________________


(18 pts) 5. A thin-walled glass sphere with radius R is filled with water. An object is placed a distance 3R from the surface of the sphere. The index of refraction for water is 4/3. Neglect the effect of the glass. How far is the final image from the object?

Ans. ___________________


(20 pts) 6. An object is between a diverging lens and a concave mirror, as shown in the diagram. The object is 25.0 cm from the vertex of the mirror and 5.0 cm from the lens. The mirror has focal length 20.0 cm and the lens has focal length -130.0 cm. Consider only the light that first reflects off the mirror and then passes through the lens.

a) Where is the image formed by the mirror? Is this image real or virtual and is it erect or inverted?

Ans. _________________

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b) Where is the final image formed by the lens? Is this image real or virtual? Is it erect or inverted, compared to the original object?

Ans. _________________

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