Physics Exam 3 Concept questions

The figure is a scaled diagram of an object and a converging lens surrounded by air. Only one focal point, F, of the lens is shown. (ch 26; 55) 55. At which of the labeled points will the image be formed? A) A B) B C) C D) D E) E

c

What can be concluded concerning the refractive indices of these three materials? (ch26; 13) A) n1 < n2 < n3 B) n1 > n2 > n3 C) n3 < n1 < n2 D) n2 < n1 < n3 E) n1 < n3 < n2

c

What does one observe on the screen in a Young's experiment if white light illuminates the double slit instead of light of a single wavelength? A) a white central fringe and no other fringes B) a dark central fringe and a series of alternating white and dark fringes on each side of the center C) a white central fringe and a series of colored and dark fringes on each side of the center D) a continuous band of colors with no dark fringes anywhere E) a dark screen since no constructive interference can occur

c

Which one of the following statements best explains why interference patterns are not usually observed for light from two ordinary light bulbs? A) Diffraction effects predominate. B) The two sources are out of phase. C) The two sources are not coherent. D) The interference pattern is too small to observe. E) Light from ordinary light bulbs is not polarized.

c

Which one of the following statements concerning a virtual image produced by a mirror is true? A) A virtual image is always larger than the object. B) A virtual image is always smaller than the object. C) A virtual image is always upright relative to the object. D) A virtual image is always inverted relative to the object. E) A virtual image can be photographed or projected onto a screen.

c

Which one of the following statements concerning rays is false? A) Rays point in the direction of the wave velocity. B) Rays point outward from the wave source. C) Rays are parallel to the wave front. D) Rays are radial lines that originate from a point source of waves. E) Rays for a plane wave are parallel to each other.

c

Which one of the following statements is true concerning the focal length of a lens? A) The focal length is the same for all colors. B) The focal length is different for different colors because of reflection. C) The focal length is different for different colors because of dispersion. D) The focal length is different for different colors because of polarization. E) The focal length is different for different colors because of spherical aberration.

c

Which one of the following statements provides the most convincing evidence that electromagnetic waves have a transverse character? A) Electromagnetic waves can be refracted. B) Electromagnetic waves can be reflected. C) Electromagnetic waves can be polarized. D) Electromagnetic waves can be diffracted. E) Electromagnetic waves exhibit interference.

c

Which one of the following statements provides the most convincing evidence that visible light is a form of electromagnetic radiation? A) Two light sources can be coherent. B) Light can be reflected from a surface. C) Light can be diffracted through an aperture. D) Light can form a double-slit interference pattern. E) Light travels through vacuum at the same speed as X-rays.

d

Which physical phenomenon is illustrated by the fact that the observer will not see all three colors of light? A) Doppler effect B) dispersion C) diffraction D) total internal reflection E) interference

d

A beam of light that consists of a mixture of red, green and violet light strikes a prism (surrounded by air) as shown. Indices of refraction for this prism for the various colors are indicated in the table. An observer is located to the right of the prism as shown. (ch 26; 36) 36. Which color(s) could, in principle, be seen by the observer? A) only red light B) only green light C) only violet light D) only green and red light E) only green and violet light

e

A plane mirror is 6 ft tall. What is its focal length? A) zero feet B) 3 ft C) 6 ft D) 12 ft E) infinity

e

An object is placed at the focal point of a converging lens of focal length f. What is the image distance? A) f B) 2f C) 1/f D) 2/f E) at an infinite distance

e

If the archer is successful in shooting the fish, what angle does the arrow make with the horizontal as it enters the water? (ch 26; 100) A) 12° B) 17° C) 23° D) 67° E) 73°

e

In the figure, Joel is using a device known as a periscope to observe an object, represented by an upright arrow. The periscope contains two plane mirrors tilted at an angle of 45° relative to Joel's line of sight. Which one of the following pairs of characteristics of the final image that Joel looks at is correct relative to those of the object? (ch 25; 9) A) inverted, real B) upright, enlarged C) inverted, smaller D) inverted, same size E) upright, virtual

e

Light of wavelength in vacuum strikes a lens that is made of glass with index of refraction 1.6. The lens has been coated with a film of thickness t and index of refraction 1.3. For which one of the following conditions will there be no reflection? A) 2t=lambda/1.6 B) 2t=lambda/1.33 C) 2t=lambda/2 D) 2t=1/2(lambda/1.6) E) 2t=1/2(lambda/1.3)

e

The index of refraction of this lens is 1.51 for red light and 1.53 for blue light. Blue light is focused at the point F. Which one of the following statements is true concerning the focal point for red light? A) It is also at F. B) It is very close to D. C) It is very close to the lens. D) It is to the left of and close to F. E) It is to the right of and close to F.

e

Which one of the following phenomena would be observed if the distance between the slits is increased? A) The fringes would become brighter. B) The central bright fringe would change position. C) The distance between dark fringes would increase. D) The distance between bright fringes would increase. E) The angular separation between the dark fringes would decrease.

e

Which one of the following phenomena would be observed if the wavelength of light were increased? A) The fringes would be brighter. B) More bright fringes would appear on the screen. C) The distance between dark fringes would decrease. D) Single-slit diffraction effects would become non-negligible. E) The angular separation between bright fringes would increase.

e

Which one of the following phrases most accurately describes paraxial rays? A) rays that pass through the principal focus B) any rays that are parallel to the principal axis C) rays that come to a focus on the principal axis D) rays close to the principal axis and parallel to it E) rays close to the principal axis, but not necessarily parallel to it

e

Which one of the following statements best explains why chromatic aberration occurs in lenses, but not in mirrors? A) The shape of the mirror prevents chromatic aberration. B) The thickness of a lens varies from top to bottom. C) The frequency of light changes when it passes through glass. D) The angle of incidence varies over the surface of a lens for incident parallel rays of light. E) Different colors of light are refracted by different amounts as the light passes through a lens.

e

Which one of the following statements best explains why the diffraction of sound is more apparent than the diffraction of light under most circumstances? A) Sound requires a physical medium for propagation. B) Sound waves are longitudinal, and light waves are transverse. C) Light waves can be represented by rays while sound waves cannot. D) The speed of sound in air is six orders of magnitude smaller than that of light. E) The wavelength of light is considerably smaller than the wavelength of sound.

e

Which one of the following statements concerning the index of refraction for a given material is true? A) The index of refraction may be less than 1. B) The index of refraction may be measured in nanometers. C) The index of refraction does not depend on the frequency of the incident light. D) For a given frequency, the index of refraction is inversely proportional to the wavelength of light in vacuum. E) For a given frequency, the index of refraction is inversely proportional to the wavelength of light in the material.

e

Which one of the following statements is not a characteristic of a plane mirror? A) The image is real. B) The magnification is +1. C) The image is always upright. D) The image is reversed right to left. E) The image and object distances are equal in magnitude.

a

Which physical phenomenon is illustrated by the fact that the prism has different refractive indices for different colors? A) Doppler effect B) dispersion C) diffraction D) total internal reflection E) interference

b

. Complete the following sentence: The term coherence relates to A) the phase relationship between two waves. B) the polarization state of two waves. C) the diffraction of two waves. D) the amplitude of two waves. E) the frequency of two waves.

a

. Which one of the following statements is true concerning a magnifying glass? A) It produces a virtual image. B) It produces an inverted image. C) It can be made from a diverging lens. D) The image distance will be less than the object distance. E) The object must be placed outside the focal point of the lens.

a

6. Five balls labeled A, B, C, D, and E are placed in front of a plane mirror as shown in the figure. Which ball(s) will the observer, in the position shown, see reflected in the mirror? (ch 25; 6) A) A only B) C only C) A and B D) A, B, D and E E) A, B, C, D and E

a

An object is placed in front of a concave spherical mirror as shown below. The three rays 1, 2, and 3, leave the top of the object and, after reflection, converge at a point on the top of the image. Ray 1 is parallel to the principal axis, ray 2 passes through F, and ray 3 passes through C. (ch25; 20) 20. Which ray(s) will pass through F after reflection? A) 1 only B) 2 only C) 3 only D) both 1 and 2 E) 1, 2, and 3

a

Complete the following statement: Fiber optics make use of A) total internal reflection. B) polarization. C) chromatic aberration. D) Brewster's angle. E) dispersion.

a

In a scene from a movie, a nearsighted character removes his eyeglasses and uses them to focus the nearly parallel rays of the sun to start a fire. What is physically wrong with this scene? A) The eyeglasses have diverging lenses and cannot be used to focus parallel rays. B) The eyeglasses have converging lenses and cannot be used to focus parallel rays. C) Sunlight cannot be used to start a fire. D) A fire can only be started if the image is virtual. E) Parallel rays cannot be focused.

a

The table lists the range of wavelengths in vacuum corresponding to a given color. Which one of these colors will produce a diffraction pattern with the widest central maximum, assuming all other factors are equal? Color Wavelength (nm) red 780 - 622 orange 622 - 597 yellow 597 - 577 green 577 - 492 blue 492 - 455 violet 455 - 390 A) red B) yellow C) green D) blue E) violet

a

Two plane mirrors are connected perpendicular to each other, as shown in the figure. If a person looks into the corner at the image straight ahead of him and closes his left eye as shown, which one of the following statements is true? (ch 25; 10) A) The left eye of the image is closed. B) The right eye of the image is closed. C) Both eyes of the image are open. D) Both eyes of the image are closed. E) There is no image straight ahead of him, so this question is meaningless.

a

When an object is placed 25 cm from a lens, a real image is formed. Which one of the following conclusions is incorrect? A) The image is upright. B) The lens is a converging lens. C) The image may be reduced or enlarged. D) The image distance can be less than 25 cm. E) The focal length of the lens is less than 25 cm.

a

Which fringe is 300 nm closer to one slit than to the other? (ch 27; 17) A) A B) B C) C D) D E) E

a

Which one of the following statements concerning the image formed by a concave spherical mirror is true? A) When the object distance is less than the focal length, the image is virtual. B) When the object distance is larger than the focal length, the image is virtual. C) When the object is at the center of curvature, the image is formed at infinity. D) When the object distance is less than the focal length, the image is inverted relative to the object. E) When the object distance is larger than the focal length, the image is upright relative to the object.

a

. Which one of the following groups of terms best describes the image? (ch25; 22) A) real, upright, enlarged B) real, inverted, reduced C) virtual, upright, enlarged D) real, inverted, enlarged E) virtual, inverted, reduced

b

A beam of light passes from air into water. Which is necessarily true? A) The frequency is unchanged and the wavelength increases. B) The frequency is unchanged and the wavelength decreases. C) The wavelength is unchanged and the frequency decreases. D) Both the wavelength and frequency increase. E) Both the wavelength and frequency decrease.

b

A fish swims 4.0 m below the surface of a still lake as shown in the figure. When an archer attempts to shoot the fish, the arrow enters the water at point P that is a horizontal distance 1.2 m from the fish. (ch 26; 98) 98. At which of the numbered positions should the archer aim to hit the fish? A) 1 B) 2 C) 3 D) 4 E) 5

b

Complete the following statement: The term dispersion refers to the fact that the index of refraction of certain materials A) depends on the Brewster angle. B) depends on the wavelength of light. C) depends on the angle of incidence. D) depends on the intensity of light. E) depends on the polarization of light.

b

Diffraction occurs when light passes through a single slit. Rank the following three choices in decreasing order, according to the extent of the diffraction that occurs (largest diffraction first): A - blue light, narrow slit B - red light, narrow slit C - blue light, wide slit Note: The blue light referred to in choices A and C is the same wavelength. Also, the narrow slit referred to in choices A and B is the same width. A) A, B, C B) B, A, C C) C, A, B D) A, C, B E) B, C, A

b

Light that is incident upon the eye is refracted several times before it reaches the retina. As light passes through the eye, at which boundary does the majority of the overall refraction occur? A) lens/aqueous humor B) air/cornea C) lens/vitreous humor D) aqueous humor/iris E) vitreous humor/retina

b

Rachel has a far point of 5 m. Which statement below concerning Rachel's vision is true? A) She has normal vision. B) She is myopic and requires diverging lenses to correct her vision. C) She is myopic and requires converging lenses to correct her vision. D) She is hyperopic and requires diverging lenses to correct her vision. E) She is hyperopic and requires converging lenses to correct her vision.

b

Red laser light passes through a single slit to form a diffraction pattern. If the width of the slit is increased by a factor of two, what happens to the width of the central maximum? Note: Assume that the angle is sufficiently small so that (sin ) is nearly equal to . A) The width of the central maximum increases by a factor of 4. B) The width of the central maximum decreases by a factor of 2. C) The width of the central maximum decreases by a factor of 4. D) The width of the central maximum increases by a factor of 2. E) The width of the central maximum does not change.

b

The figure shows the interference pattern obtained in a double-slit experiment using light of wavelength 600 nm. v (ch 27; 15) 15. Which fringe is the same distance from both slits? A) A B) B C) C D) D E) E

b

Two identical light waves, A and B, are emitted from different sources and meet at a point P. The distance from the source of A to the point P is LA; and the source of B is a distance LB from P. Which one of the following statements is necessarily true concerning the interference of the two waves? A) A and B will interfere constructively because their amplitudes are the same. B) A and B will interfere constructively if LA = LB. C) A and B will interfere destructively if LA - LB = m where m = 0, 1, 2, 3, ... D) A and B will interfere destructively if LA is not equal to LB. E) A and B will interfere constructively because their wavelengths are the same.

b

When an object is placed 15 cm from a lens, a virtual image is formed. Which one of the following conclusions is incorrect? A) The lens may be a convex or concave. B) If the image is upright the lens must be a diverging lens. C) If the image is reduced, the lens must be a diverging lens. D) If the lens is a diverging lens, the image distance must be less than 15 cm. E) If the lens is a converging lens, the focal length must be greater than 15 cm.

b

Which one of the following statements is true concerning this situation? A) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 13°. B) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 63°. C) When the angle of incidence is equal to the Brewster angle, the angle of refraction is 42°. D) Since the Brewster angle is less than the critical angle, there is no refraction when the angle of incidence is equal to B. E) Since the Brewster angle is greater than the critical angle, there is no refraction when the angle of incidence is equal to B.

b

Which pair of terms most accurately describes the image? (ch 26; 56) A) real, upright B) real, inverted C) virtual, upright D) virtual, inverted E) virtual, reduced

b

Which physical phenomenon is illustrated by the fact that the emerging rays are spread into the component colors of the beam? A) Doppler effect B) dispersion C) diffraction D) total internal reflection E) interference

b

. A ray of blue light travels through air and is refracted as it enters a glass prism shown in the figure. An unknown liquid is in contact with the right side of the prism. The light then follows the path shown. Which one of the following statements concerning this situation is true? (ch 26; 30) A) The frequency of the light changes inside the prism. B) The index of refraction of the glass is smaller than that of air. C) The index of refraction of the unknown liquid is the same as that of the glass. D) The speed of light is larger in the liquid than in the glass. E) The refractive index of the liquid is the same as that of air.

c

. Which ray(s) will reflect back on itself (themselves)? (ch25; 21) A) 1 only B) 2 only C) 3 only D) both 1 and 2 E) 1, 2, and 3

c

A physics student desires to create a beam of light that consists of parallel rays. Which one of the following arrangements would allow her to accomplish this task? A) A light bulb is placed at the focal point of a convex mirror. B) A light bulb is placed at the focal point of a diverging lens. C) A light bulb is placed at the focal point of a converging lens. D) A light bulb is located at twice the focal length from a concave mirror. E) A light bulb is located at twice the focal length from a converging lens.

c

An object is placed near two perpendicular plane mirrors as shown in the figure. How many images will be formed? (ch 25; 4) A) 1 B) 2 C) 3 D) 4 E) 5

c

In a Young's double slit experiment, green light is incident on the two slits. The interference pattern is observed on a screen. Which one of the following changes would cause the fringes to be more closely spaced? A) Reduce the slit separation distance. B) Use red light instead of green light. C) Use blue light instead of green light. D) Move the screen farther away from the slits. E) Move the light source farther away from the slits.

c

White light enters a glass prism, but the color components of the light are observed to emerge from the prism. Which one of the following statements best explains this observation? A) The separation of white light into its color components is due to the increase in the speed of light within the glass. B) Some of the color components of the white light are absorbed by the glass and only the remaining components are observed. C) The index of refraction of the glass depends on the wavelength, so the color components are refracted at different angles. D) Only some of the color components are refracted by the glass; and these are the ones that are observed. E) White light is separated into its color components by total internal reflection within the prism.

c

. A ray of light originates in medium A and is incident upon medium B. For which one of the following pairs of indices of refraction for A and B is total internal reflection not possible? nA nB A) 1.36 1.00 B) 1.26 1.15 C) 2.54 1.63 D) 1.28 1.36 E) 1.12 1.06

d

. An object is placed 20.0 cm in front of a convex spherical mirror with radius of curvature 60.0 cm. Which one of the following phrases best describes the image? A) virtual and located at infinity B) real and located 12 cm from the mirror C) real and located 17 cm from the mirror D) virtual and located 12 cm from the mirror

d

An object is placed 20 cm in front of a concave spherical mirror that has a radius of curvature 60 cm. Which one of the following phrases best describes the image? A) virtual and located at infinity B) real and located 60 cm from the mirror C) real and located 120 cm from the mirror D) virtual and located 60 cm from the mirror E) virtual and located 120 cm from the mirror

d

An object is placed at the focal point of a thin diverging lens of focal length f. What is the image distance? A) f B) 2f C) 1/f D) f/2 E) at an infinite distance

d

The bending of light as it moves from one medium to another with differing indices of refraction is due to a change in what property of the light? A) amplitude B) period C) frequency D) speed E) color

d

The compound microscope discussed in Cutnell and Johnson's text is made from two lenses. Which one of the following statements is true concerning the operation of this microscope? A) Both lenses form real images. B) Both lenses form virtual images. C) Only the lens closest to the eye forms an image. D) The lens closest to the object forms a real image; the other lens forms a virtual image. E) The lens closest to the object forms a virtual image; the other lens forms a real image.

d

The system is immersed in a fluid other than air that has an index of refraction that is larger than that of the lens. Which one of the following statements is true concerning this new situation? A) The image will be real. B) The image will be inverted. C) The image will be enlarged relative to the object. D) The image will be formed on the same side of the lens as the object. E) The lens may act as a diverging lens or a converging lens depending on the location of the object.

d

Two glass plates, each with an index of refraction of 1.55, are separated by a small distance D. The space between the plates is filled with water (n = 1.33) as shown. For which one of the following conditions will the reflected light appear green? Note: The wavelength of green light is 460 nm in vacuum. (ch 27; 28) A) 2D=(460nm/1.55) B) D=L/2(460nm/1.55) C) D=(460nm/1.55) D) 2D=1/2(460nm/1.33) E) 2D=(460nm/1.33)

d

When an object is placed 20 cm from a diverging lens, a reduced image is formed. Which one of the following statements is necessarily true? A) The image is inverted. B) The image could be real. C) The image distance must be greater than 20 cm. D) The focal length of the lens may be less than 20 cm. E) The refractive power of the lens must be greater than 0.05 diopters.

d

Which fringe results from a phase difference of 4? (ch 27; 18) A) A B) B C) C D) D E) E

d

Which one of the following figures shows the smallest angle of incidence in the water for which no light emerges into air? (ch 26; 102) Note: Only one figure is physically possible. A) a B) b C) c D) d E) e

d

Which one of the following phrases most accurately describes the image of the fish as seen by the archer? (ch 26; 99) A) real and inverted B) virtual and inverted C) real and reversed right to left D) virtual with its orientation unaltered E) real with its orientation unaltered

d

Which one of the following phrases most accurately describes the term wave front? A) the surface of a plane mirror B) the surface of a convex mirror C) a surface upon which a wave is incident D) a surface of constant phase within a wave E) a surface that is parallel to the direction of wave propagation

d

. Santa Claus looks at his reflection in a spherical Christmas tree ornament. Which one of the following statements concerning Santa's image is true? A) The image must be real. B) The image is farther from the ornament than Santa is. C) The image is larger than Santa. D) The image must be inverted. E) The image must be smaller than Santa.

e

. Which fringe is the third order maximum? (ch 27; 16) A) A B) B C) C D) D E) E

e

. Which one of the following statements concerning a convex mirror is true? A) A convex mirror can form a real image. B) A convex mirror must be spherical in shape. C) The image produced by a convex mirror will always be inverted relative to the object. D) A convex mirror produces a larger image than a plane mirror does for the same object distance. E) The image a convex mirror produces is closer to the mirror than it would be in a plane mirror for the same object distance.

e