PHYS 2326 Practice Final with Keys PDF

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) An index of refraction less than one for a medium would imply that 1) A) that the speed of light in the medium is greater than the spe...

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) An index of refraction less than one for a medium would imply that 1) A) that the speed of light in the medium is greater than the speed of light in vacuum. B) that the speed of light in the medium is less than the speed of light in vacuum. C) that the speed of light in the medium is the same as the speed of light in vacuum. D) reflection is not possible. E) refraction is not possible. 2) When light enters a material of higher index of refraction, its speed 2) A) stays the same. B) decreases. C) first increases then decreases. D) increases. E) first decreases then increases. 3) Another name for the POLARIZING ANGLE is the 3) A) Land angle. B) refracted angle. C) Moles angle. D) Brewster angle. 4) Spherical lenses suffer from 4) A) both spherical and chromatic aberration. B) chromatic aberration, but not spherical aberration. C) neither spherical nor chromatic aberration. D) spherical aberration, but not chromatic aberration. 5) A personʹs face is 30 cm in front of a concave shaving mirror. If the image is an erect image 1.5 5) times as large as the object, what is the mirrorʹs focal length? A) 70 cm B) 30 cm C) 20 cm D) 50 cm E) 90 cm 6) Consider two diffraction gratings with the same slit separation, the only difference being that one 6) grating has 3 slits and the other 4 slits. If both gratings are illuminated with a beam of the same monochromatic light A) the grating with 3 slits produces the greater separation between orders. B) both gratings produce the same separation between orders. C) both gratings produce the same separation between orders, but the orders are better defined with the 4-slit grating. D) the grating with 4 slits produces the greater separation between orders. 7) Which of the following materials has the slowest speed of light? 7) A) oil B) flint glass C) diamond D) air E) water 8) The rear-view mirrors on the passenger side of many new cars have a warning written on them: 8) ʺOBJECTS IN MIRROR ARE CLOSER THAN THEY APPEAR.ʺ This implies that the mirror must be A) concave. B) plane. C) transparent. D) convex. 9) A ray of light, which is traveling in air, is incident on a glass plate at a 45° angle. The angle of 9) refraction in the glass A) is equal to 45°. B) is less than 45°. C) is unknown because it all depends on the index of refraction of glass. D) is greater than 45°. 1 10) The image of the rare stamp you see through a magnifying glass is 10) A) either the same orientation or upside-down, depending on how close the stamp is to the glass. B) always the same orientation as the stamp. C) always upside-down compared to the stamp. D) either the same orientation or upside-down, depending on the thickness of the glass used. FIGURE 22-2 11) A light beam composed of red and blue light is incident upon a rectangular glass plate, as shown 11) in Fig. 22-2. The light emerges into the air from point P as two separate beams A) that are parallel, with the blue beam displaced below the red beam. B) that are not parallel, with the red beam displaced below the blue beam. C) that are parallel, with the red beam displaced below the blue beam. D) that are not parallel, with the blue beam displaced below the red beam. 12) Consider a converging lens. If the object is inside the focal point, then the image will always be 12) A) virtual. B) at the focal point. C) at infinity. D) real. 13) The critical angle for a beam of light passing from water into air is 48.8°. This means that all light 13) rays with an angle of incidence greater than this angle will be A) totally polarized. B) totally transmitted. C) absorbed. D) partially reflected and partially transmitted. E) totally reflected. 14) The path difference for destructive interference is mλ/2 where 14) A) m = 1, 3, 5, 7,... B) m = 0, 1, 2, 3,... C) m = 0, 2, 4, 6,... D) m = 1, 2, 3, 4,... E) m = 2, 4, 6 , 8,... 15) The condition 2d sin(θ) = nλ for X-ray diffraction maxima is attributed to 15) A) Land. B) Young. C) Rayleigh. D) Brewster. E) Bragg. 2 16) The index of refraction of a certain medium is 1.5. What is the speed of light in that medium? 16) A) 4.0 × 108 m/s B) 2.0 × 108 m/s C) 1.0 × 108 m/s D) 3.0 × 108 m/s E) 5.0 × 108 m/s FIGURE 24-1 17) Monochromatic light from a distant source is incident on two parallel narrow slits. After passing 17) through the slits the light strikes a screen, as shown in Fig. 24 -1. What will be the nature of the pattern of light observed on the screen? A) There will be two bright bands of light, one in line with each slit. B) The screen will be uniformly illuminated except for two dark bands, one in line with each slit. C) There will be a series of alternating light and dark bands. D) The screen will be most brightly illuminated at point O, with the intensity decreasing slowly and uniformly as you move outward from point O. E) A rainbow of colored lines will be seen spreading out on either side of point O. 18) In a two-slit experiment, the third bright fringe away from the central fringe is observed at an 18) angle of 7.0°. If the wavelength of the light is 490 nm, what is the distance between the two slits? A) 4.0 × 10-6 m B) 2.1 × 10-5 m C) 2.1 × 10-6 m D) 3.6 × 10-5 m E) 1.2 × 10-5 m 19) What do we mean when we say that two light rays striking a screen are in phase with each other? 19) A) They have the same wavelength. B) They are traveling at the same speed. C) They alternately reinforce and cancel each other. D) When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. 20) When a light wave enters into a medium of different optical density 20) A) its speed, frequency, and wavelength change. B) its frequency and wavelength change. C) its speed and frequency change. D) its speed and wavelength change. 3 21) How far from a lens of focal length 50.0 mm must the object be placed if it is to form a virtual 21) image magnified in size by a factor of three? A) 54.4 mm B) 48.0 mm C) 33.3 mm D) 38.3 mm E) 42.2 mm 22) If an X-ray beam of wavelength 1.4 × 10-10 m makes an angle of 20° with a set of planes in a 22) crystal causing first order constructive interference, at what angle will the second order line appear? A) 4° B) 40° C) 43° D) 20° E) 11° FIGURE 22-4 23) A light ray emerges from the bottom of a 45° glass prism into air, as shown in Fig. 22-4. From 23) which direction was the ray incident on the prism? A) D B) A C) C D) B 24) Two parallel rays (also parallel to the optic axis) reflect from a concave mirror. They intersect at 24) A) a point behind the mirror. B) the center of curvature. C) infinity. D) the focal point. 25) Light traveling at an angle into a denser medium is refracted 25) A) away from the normal. B) equally. C) perpendicular to the normal. D) parallel to the normal. E) toward the normal. 26) Light travels fastest 26) A) through diamond. B) through glass. C) in a vacuum. D) through water. E) through plastic. 27) An object is placed 50 cm in front of a concave mirror with a focal length of 25 cm. What is the 27) magnification? A) -0.50 B) -1.0 C) -2.5 D) -2.0 E) -1.5 4 28) Spherical mirrors suffer from 28) A) spherical aberration, but not chromatic aberration. B) chromatic aberration, but not spherical aberration. C) both spherical and chromatic aberration. D) neither spherical nor chromatic aberration. 29) What is the index of refraction inside a certain transparent material if the critical angle is found to 29) be 48.° (air is outside)? A) 1.22 B) 1.49 C) 1.48 D) 0.743 E) 1.35 30) A ray of light consisting of blue light (wavelength 480 nm) and red light (wavelength 670 nm) is 30) incident on a thick piece of glass at 80°. What is the angular separation between the refracted red and refracted blue beams while they are in the glass? (The respective indices of refraction for the blue light and the red light are 1.4636 and 1.4561.) A) 0.455° B) 0.341° C) 0.330° D) 0.155° E) 0.277° 31) If you stand in front of a convex mirror, at the same distance from it as its radius of curvature, 31) A) you wonʹt see your image because there is none. B) you will see your image and you will appear larger. C) you will see your image and you will appear smaller. D) you will see your image at your same height. E) you wonʹt see your image because itʹs focused at a different distance. 32) An ideal polarizer is placed in a beam of unpolarized light and the intensity of the transmitted 32) light is 1. A second ideal polarizer is placed in the beam with its preferred direction rotated 40° to that of the first polarizer. What is the intensity of the beam after it has passed through both polarizers? A) 0.64 B) 0.59 C) 0.30 D) 0.77 E) 0.41 33) When light passes through a prism the color refracted most is 33) A) yellow. B) red. C) green. D) violet. E) blue. 34) For a beam of light, the direction of polarization is defined as 34) A) the beamʹs direction of travel. B) the direction of the electric fieldʹs vibration. C) the direction that is mutually perpendicular to the electric and magnetic field vectors. D) the direction of the magnetic fieldʹs vibration. 35) A double convex (convex-convex) thin lens has radii of curvature 46. cm, and is made of glass of 35) index of refraction n = 1.60. What is the focal length? A) 38 cm B) 46. cm C) 18. cm D) 36. cm E) infinite 36) A soap film is being viewed in white light. As the film becomes very much thinner than the 36) wavelength of blue light, the film A) appears black because it reflects no visible light. B) appears red since all other colors are transmitted. C) appears white because it reflects all wavelengths of visible light. D) appears blue since all other colors are transmitted. 5 37) Consider two diffraction gratings; one has 4000 lines per cm and the other one has 6000 lines per 37) cm. A) Both gratings produce the same dispersion, but the orders are sharper for the 4000 -line grating. B) Both gratings produce the same dispersion, but the orders are sharper for the 6000 -line grating. C) The 6000-line grating produces the greater dispersion. D) The 4000-line grating produces the greater dispersion. 38) In a double-slit experiment, it is observed that the distance between adjacent maxima on a remote 38) screen is 1 cm. What happens to the distance between adjacent maxima when the slit separation is cut in half? A) It decreases to 0.25 cm. B) It increases to 4 cm. C) It increases to 2 cm. D) It decreases to 0.5 cm. 39) Light enters air from water. The angle of refraction will be 39) A) less than or equal to the angle of incidence. B) less than the angle of incidence. C) greater than or equal to the angle of incidence. D) equal to the angle of incidence. E) greater than the angle of incidence. 40) In common transparent media, as the frequency of light increases, the index of refraction 40) A) decreases. B) increases. C) varies as the sine of the incident angle. D) stays constant. 41) What kind of lens is it that has a power of +10 Diopters and a first surface center of curvature in 41) front of the lens? A) converging meniscus B) plano convex C) double convex D) double concave E) plano concave 42) Liquid Crystal Displays (LCDs) depend upon which of the following for their operation? 42) A) coherence B) thin film interference C) polarization D) dichroism E) diffraction 43) Sometimes when you look into a curved mirror you see a magnified image (a great big you!) and 43) sometimes you see a diminished image (a little you). If you look at the bottom (convex) side of a shiny spoon, what will you see? A) You will either see a little you or a great big you, depending on how near you are to the spoon. B) You will see a little you, right side up. C) You will see a little you, but whether you are right side up or upside down depends on how near you are to the spoon. D) You wonʹt see an image of yourself because no image will be formed. E) You will see a little you, upside down. 6 44) When a ray of light passes obliquely from one medium to another, which of the following 44) changes? A) direction of travel B) wavelength C) wavelength, speed, & direction of travel D) speed E) speed, direction of travel, but not wavelength 45) The sky appears ʺblueʺ because of 45) A) birefringence. B) Braggʹs Law. C) Rayleigh scattering. D) Brewsterʹs polarization. E) dichroism. 46) What is the limiting angle of resolution for the eye if the pupil diameter of the eye is 4.0 mm, a 46) wavelength of light of 600 nm and index of refraction for the eye equal to 1.34? A) 2.6 × 10-4 rad B) 4.2 × 10-4 rad C) 1.4 × 10-4 rad D) 2.1 × 10-4 rad E) 1.1 × 10-4 rad 47) The images formed by concave lenses 47) A) are always virtual. B) could be real or virtual, but always real when the object is placed at the focal point. C) are always real. D) could be real or virtual; it depends on whether the object distance is smaller or greater than the focal length. 48) Fiber optics depends upon the phenomenon of 48) A) polarization. B) absorption. C) total internal reflection. D) dispersion. E) diffuse reflection. 49) The colors on an oil slick are caused by reflection and 49) A) interference. B) polarization. C) diffraction. D) refraction. 50) If you stand in front of a concave mirror, exactly at its center of curvature, 50) A) you will see your image at your same height; however it will be inverted. B) you wonʹt see your image because itʹs focused at a different distance. C) you wonʹt see your image because there is none. D) you will see your image and you will appear smaller. E) you will see your image and you will appear larger. 7 51) If you stand in front of a double-concave mirror, exactly at its center of curvature, your image will 51) appear where you are, but A) larger and upside down. B) the same size and upright. C) the same size and upside down. D) larger and upright. 52) Chromatic aberration occurs because of 52) A) internal reflection. B) astigmatism. C) spherical surfaces. D) polarization. E) dispersion. 53) Rainbows are caused by sunlight being 53) A) reflected. B) refracted. C) dispersed, refracted, & reflected. D) refracted & reflected but not dispersed. E) dispersed. 54) If the refractive index of the glass in a lens varies with wavelength, then which of the following 54) results? A) chromatic aberration B) total reflection C) light scattering D) spherical aberration E) astigmatism 55) When TOTAL REFLECTION occurs at a surface, the incident angle must be in the substance with 55) the higher A) index of refraction. B) incident angle. C) speed of light. D) c/n. 56) What is the critical angle for light traveling from crown glass (n = 1.52) into water (n = 1.33)? 56) A) 61° B) 48° C) 57° D) 42° E) 66° 57) When a beam of light, which is traveling in air, is reflected by a glass surface, there is 57) A) a 90° phase change in the reflected beam. B) a 45° phase change in the reflected beam. C) a -45° phase change in the reflected beam. D) a 180° phase change in the reflected beam. E) no phase change in the reflected beam. 58) The index of refraction of diamond is 2.42. This means that a given wavelength of light travels 58) A) 2.42 times faster in vacuum than it does in diamond. B) 2.42 times faster in diamond than it does in vacuum. C) 2.42 times faster in diamond than it does in air. D) 2.42 times faster in air than it does in diamond. E) 2.42 times faster in vacuum than it does in air. 8 59) At the first maxima on either side of the central bright spot in a double-slit experiment, light from 59) each opening arrives A) in phase. B) -45° out of phase. C) 90° out of phase. D) 180° out of phase. E) 45° out of phase. 60) When a beam of light, which is traveling in glass, strikes an air boundary, there is 60) A) a 180° phase change in the reflected beam. B) a 90° phase change in the reflected beam. C) a -45° phase change in the reflected beam. D) a 45° phase change in the reflected beam. E) no phase change in the reflected beam. 9 Answer Key Testname: PHYS 1402 PRACTICE FINAL 1) A 2) B 3) D 4) A 5) E 6) C 7) C 8) D 9) B 10) A 11) A 12) A 13) E 14) A 15) E 16) B 17) C 18) E 19) D 20) D 21) C 22) C 23) A 24) D 25) E 26) C 27) B 28) A 29) E 30) E 31) C 32) B 33) D 34) B 35) A 36) A 37) C 38) C 39) E 40) B 41) A 42) C 43) B 44) C 45) C 46) C 47) A 48) C 49) A 50) A 10 Answer Key Testname: PHYS 1402 PRACTICE FINAL 51) C 52) E 53) C 54) A 55) A 56) A 57) D 58) A 59) A 60) E 11