Q&A Hero

Q: An object 30 cm in front of a concave spherical mirror (f= 10 cm) is moved toward the mirror until it is 20 cm from it. Sketch ray diagrams for these cases and estimate the factor by which the image magnification changes.

Q: An object is placed 20 cm from a converging spherical lens. Sketch ray diagrams and give the general characteristics of the image for (a) a lens with a focal length of f= 15 cm and (b) a lens with a focal length of f= 25 cm.

Q: A plane mirror stands vertically on a table. A ruler lies on the table in such a position as to make an angle of 30 with the mirror. Determine the angle between the ruler and its image.

Q: An object is placed 20 cm in front of a concave spherical mirror. Sketch ray diagrams and give the general characteristics of the images for mirrors with radii of curvature of (a) R= 30 cm and (b) R= 10 cm.

Q: The speed of light in a particular transparent medium is 5/8 the speed of light in a vacuum. What is the index of refraction of the material?

Q: A particular material has an index of refraction of 1.25. What percent of the speed of light in a vacuum is the speed of light in the material?

Q: The speed of light in diamond is 1.24 108m/s. What is the index of refraction of diamond?

Q: The photoreceptors responsible for color vision are called ______________.

Q: For normal vision, an object can be seen clearly when it is beyond the _____________.

Q: Unlike spherical mirrors, spherical lenses do nothave a focal length equal to _____________.

Q: The image of a convex mirror is always virtual, _________, and smaller.

Q: When an object is inside the focal point of a concave mirror, a(n) _______________ image always results.

Q: A person who can clearly see nearby objects but not distant ones is ______________.

Q: A lens that is thicker at the center than at the edge is called a(n) ______________ lens.

Q: A(n) ______________ image cannot be focused on a screen.

Q: A(n) ______________ image is defined as one that can be brought to a focus on a screen.

Q: The waveform of interfering waves is described by the principle of ______________.

Q: Complete destructive interference occurs for two waves of the same amplitude and frequency when the waves are ______________ degrees out of phase.

Q: FM radio reception may be blocked by buildings because the wavelengths are too short to be ______________ around buildings.

Q: A(n) ______________ consists of many narrow parallel slits very close together.

Q: The change in wave motion produced by phase and amplitude relations of two or more waves is called a(n) ______________ effect.

Q: A diamond is said to have "fire" because of ______________.

Q: A change in the direction of a wave as a result of its encountering a sharp edge or a slit is called ______________.

Q: ______________ waves cannot be polarized.

Q: Liquid crystal displays (LCDs) make use of the wave phenomenon called ______________.

Q: Polarizing sunglasses have the transmission axis oriented ______________.

Q: The preferential orientation of the EM field vectors of light is called __________________.

Q: If we restrict the vibrations of the electric field vector of a wave to one direction, the wave is said to be linearly ______________.

Q: For total internal reflection, light is reflected and none is ______________.

Q: Total internal reflection occurs when the angle of incidence of the light is greater than the _________ angle.

Q: Light traveling from a more dense to a less dense medium is refracted ______________ the normal.

Q: When light enters a denser medium, the speed of the light ______________.

Q: When light strikes a transparent medium, some light is reflected and some is ____________.

Q: A change in the direction of a wave because of a change in the velocity of the wave is called ______________.

Q: When a wave is ______________, the angle of reflection equals the angle of incidence.

Q: According to the law of reflection, the angle of reflection is equal to ______________.

Q: Reflection from rough surfaces is called ______________ reflection.

Q: Reflection from smooth surfaces is called ______________ reflection.

Q: A change in the direction of a wave resulting from its meeting an opaque material is called ______________.

Q: Optics is divided into ray optics and ______________ optics.

Q: For total internal reflection, light is ______________ and none is ______________. A) reflected, refracted B) refracted; transmitted C) transmitted, refracted D) transmitted; reflected

Q: For total internal reflection, light is ______________ and none is ______________. A) refracted; reflected B) refracted; transmitted C) reflected; transmitted D) transmitted; reflected

Q: The photoreceptors responsible for "twilight" vision are called A) rods. B) cylinders. C) cones. D) cans.

Q: The photoreceptors responsible for color vision are called A) rods. B) cylinders. C) cones. D) cans.

Q: For normal vision, an object can be seen clearly when it is beyond the A) far point. B) nearsighted point. C) farsighted point. D) near point.

Q: A visual defect wherein a person can see nearby objects clearly but not distant objects is called A) dispersion. B) destructive interference. C) farsightedness. D) nearsightedness.

Q: A visual defect wherein a person can see distant objects clearly but not nearby objects is called A) dispersion. B) destructive interference. C) farsightedness. D) nearsightedness.

Q: The image of a real object formed by a single converging lens cannotbe A) real, inverted, and enlarged. B) real, inverted, and the same size as the object. C) virtual, upright, and enlarged. D) real, inverted, and reduced. E) virtual, upright, and reduced.

Q: A diverging lens produces an image of a real object. This image is A) reduced, upright, and virtual. B) enlarged, inverted, and real. C) reduced, inverted, and virtual. D) enlarged, upright, and real. E) enlarged, upright, and virtual.

Q: The image formed by a diverging spherical lens is always A) upright. B) reduced. C) virtual. D) all of these.

Q: A(n) ______________ image is defined as one that cannot be brought to a focus on a screen. A) virtual B) real C) upright D) inverted

Q: A(n) ______________ image is defined as one that can be brought to a focus on a screen. A) virtual B) real C) upright D) inverted

Q: The image of a convex mirror is always A) virtual, inverted, and larger. B) virtual, upright, and smaller. C) real, upright, and smaller. D) real, inverted, and larger.

Q: The image of an object at the focal point of a concave spherical mirror A) looks the same as the object. B) is said to be formed at infinity. C) is real. D) is reduced.

Q: Images of objects are formed by lenses because of A) refraction. B) diffraction. C) internal reflection. D) all of these.

Q: A lens that thicker at the edge than at the center is A) a diverging lens only. B) a convex lens only. C) a converging lens only. D) both a convex lens and a converging lens.

Q: A lens that is thicker at the center than at the edge is A) a diverging lens only. B) a convex lens only. C) a converging lens only. D) both a convex lens and a converging lens.

Q: An object is placed at the center of curvature of a concave mirror. The image is A) inverted, real, and the same size as the object. B) virtual and the same size as the object. C) virtual and smaller than the object. D) virtual and enlarged. E) erect, real, and the same size as the object.

Q: All real images A) cannot be focused on a screen. B) are erect. C) can be focused on a screen. D) are inverted.

Q: A concave mirror will produce A) only inverted images. B) real or virtual images. C) only virtual images. D) only real images.

Q: An example of a converging spherical mirror is a A) flashlight reflector. B) bathroom mirror. C) spherical truck mirror. D) hubcap.

Q: An example of a diverging spherical mirror is A) a bathroom mirror. B) a round Christmas tree ornament. C) a flashlight reflector. D) none of these.

Q: An object is placed 10 cm to the left of a converging spherical lens. The lens has a focal length of f= 25 cm. What kind of image is formed and what is its orientation? A) Real/Upright B) Virtual/Upright C) Virtual/Inverted D) Real/Inverted

Q: An object is placed 5 cm to the left of a converging spherical lens. The lens has a focal length of f= 10 cm. Where is the image formed and what kind of image is formed? A) 10 cm to the right of the lens, Real B) 10 cm to the left of the lens, Virtual C) 10 cm to the right of the lens, Virtual D) 10 cm to the left of the lens, Real

Q: An object is placed 10 cm to the left of a converging spherical lens. The lens has a focal length of f= 25 cm. Where is the image formed? A) 7.1 cm to the right of the lens B) 7.1 cm to the left of the lens C) 17 cm to the right of the lens D) 17 cm to the left of the lens

Q: The leastdiffraction occurs for A) l< d. B) l= d. C) l> d. D) none of these; that is, it makes no difference.

Q: The greatest diffraction occurs for A) l< d. B) l= d. C) l> d. D) none of these; that is, it makes no difference.

Q: The change in the direction of a wave resulting from its encountering a small slit is known as A) interference. B) diffraction. C) reflection. D) polarization.

Q: The bending of light rays around corners is called A) reflection. B) refraction. C) interference. D) diffraction.

Q: Light for which the electric field vector is restricted to one plane is said to be A) linearly polarized. B) linearly refracted. C) linearly reflected. D) unpolarized.

Q: A liquid crystal display (LCD) using a "twisting" effect in the display involves A) polarization. B) interference. C) refraction. D) diffraction.

Q: Polarization involves A) the orientation of field vectors. B) only longitudinal waves. C) diffraction. D) interference.

Q: The trapping of light in "light pipes," or fiber optics, is due to A) total internal reflection. B) refraction. C) absorption of the outside light. D) diffraction.

Q: Dispersion occurs in a medium because A) the index of refraction depends on wave amplitude. B) of regular reflection. C) of diffuse reflection. D) the index of refraction depends on the wavelength.

Q: If a ray of light passes from air into glass, the light will A) travel along the normal. B) bend toward the normal. C) bend away from the normal. D) continue traveling in the same direction.

Q: If a ray of light passes from air into glass, the angle of incidence will be A) less than the angle of refraction. B) sometimes greater and sometimes less than the angle of refraction. C) greater than the angle of refraction. D) equal to the angle of refraction.

Q: The observation of a "wet spot" on a hot highway in the summer is caused by A) dispersion. B) diffraction. C) refraction. D) reflection.

Q: The separation of white light into its component colors is called A) polarization. B) diffraction. C) dispersion. D) refraction.

Q: When light enters a denser medium and is refracted, A) the wavelength is unchanged. B) the wave speed increases. C) the frequency is unchanged. D) the wavelength increases.

Q: The index of refraction of transparent materials is A) equal to 1. B) greater than 1. C) less than 1. D) any of these.