Q&A Hero

Q: A wave with a high frequency has a relatively A) short wavelength. B) long wavelength. C) both of these D) none of the above

Q: Both a radio wave and light wave have identical A) speeds. B) wavelengths. C) frequencies. D) all of the above E) none of the above

Q: A sound wave and a light wave have identical A) speeds. B) wavelengths. C) frequencies. D) all of the above E) none of the above

Q: The main difference between a radio wave and a sound wave is A) frequency. B) wavelength. C) energy. D) amplitude. E) basic nature.

Q: Both sound and light can travel in A) a vacuum. B) water. C) both of these D) none of the above

Q: Which have the longest wavelengths when traveling in a vacuum? A) radio waves B) light C) X-rays D) all the same

Q: Which travels fastest in a vacuum? A) radio waves B) light C) X-rays D) all the same

Q: Electromagnetic waves can travel in A) a vacuum. B) water. C) both of these D) none of the above

Q: Electromagnetic waves consist of A) compressions and rarefactions of electromagnetic pulses. B) vibrating electric and magnetic fields. C) particles of light energy. D) high-frequency sound waves.

Q: Which of the following is fundamentally different from the others? A) sound waves B) X rays C) gamma rays D) light waves E) radio waves

Q: Which of these has a higher frequency than visible light? A) radio wave B) microwave C) infrared wave D) ultraviolet wave E) all do

Q: Which of the following occupies the smallest percentage of the electromagnetic spectrum? A) radio waves B) microwaves C) visible light D) gamma rays

Q: The frequency of an electromagnetic wave and the frequency of the vibrating electrons that produce it are A) nearly the same. B) the same. C) quite different.

Q: A changing electric field induces a changing A) magnetic field. B) electromagnetic field. C) both of these D) neither of these

Q: The source of electromagnetic waves is vibrating A) electric charges. B) atoms. C) molecules. D) energy fields.

Q: Electromagnetic waves consist of A) compressions and rarefactions of electromagnetic pulses. B) oscillating electric and magnetic fields. C) particles of light energy. D) high-frequency sound waves.

Q: Most of the waves in the electromagnetic spectrum are A) red light. B) blue light. C) green light. D) invisible.

Q: If an electric charge is rapidly shaken up and down, A) sound is emitted. B) light is emitted. C) electron excitation occurs. D) an electromagnetic wave is produced.

Q: When viewing a seascape, what is a major difference in the effect of wearing polarizing sunglasses versus sunglasses that simply cut down on intensity?

Q: Why does a swimmer under water see the color of seawater as greenish blue?

Q: Explain why the sky is blue.

Q: On a TV screen, red, green, and blue spots of light produce a full spectrum of colors. What spots are activated to produce yellow? Red? Magenta? White?

Q: What are the three primary colors for light addition? What colors appear when light of only two primary colors are shone on a white screen? How would the color purple be produced?

Q: What accounts for the additional few minutes of sunlight we experience daily, before sunrise and after sunset?

Q: If you walk at a constant pace across a room of known length, your walking speed is the room length divided by the time to cross the room. Now suppose you repeat your walk but briefly stop along the way to interact with people sitting along your path. What effect does this have on your average speed across the room? How is this analogous to light passing through glass? In what way is it not analogous?

Q: Why is ultraviolet light not transmitted by glass?

Q: Describe a model for explaining how light is transmitted through glass.

Q: Because of absorption, a Polaroid will actually transmit about 40% of incident nonpolarized light. Two Polaroids with their axes aligned will transmit A) 0%. B) 40%. C) 100%. D) between 0% and 40%. E) between 40% and 100%.

Q: An ideal Polaroid will transmit 50% of nonpolarized incident light. How much light is transmitted by two ideal Polaroids oriented with their axes parallel to each other? A) 0% B) 50% C) 100% D) between 0% and 50% E) between 50% and 100%

Q: The amount of light from an incandescent lamp that is transmitted through an ideal Polaroid filter is half, and through a real Polaroid filter is A) less than half. B) more than half. C) half.

Q: Because most reflecting surfaces are horizontal, the polarization axes of ordinary sunglasses are A) vertical. B) horizontal. C) at right angles to each other.

Q: The glare seen from water in a lake is largely A) horizontally polarized. B) vertically polarized. C) nonpolarized.

Q: Light will not pass through a pair of Polaroids when their axes are A) parallel. B) perpendicular. C) 45 to each other. D) all of the above E) none of the above

Q: The direction of vibration for an electron and the plane of polarization of the light it emits A) are the same. B) are at right angles to each other. C) may or may not be at right angles to each other. D) are independent of each other.

Q: Polarization is a property of A) transverse waves. B) longitudinal waves. C) both of these D) none of the above

Q: Poke a pinhole in a piece of card and hold it in sunlight and an image of the Sun is cast on the floor. The Sun-image diameter depends on the height of the pinhole above the floor. Measurements for all heights show the Sun-image diameter is about 1/100 the distance between the pinhole and the floor. This means that A) about 100 end-to-end Sun images would fit between the pinhole and the floor. B) distance-wise, the Sun is about 100 Suns away from Earth. C) both of these D) none of the above

Q: When the tiny hole in a pinhole camera is made larger, the image is A) brighter but less clear. B) clearer. C) right-side up. D) none of the above

Q: Small openings between leaves in a tree act as pinholes. The round spots of light cast on the ground below are images of A) the Sun. B) the openings themselves. C) both of these D) neither of these

Q: The image in a pinhole camera is A) always inverted. B) sometimes inverted. C) always right-side up.

Q: When a pulse of white light is incident on a piece of glass, the first color to emerge is A) red. B) orange. C) green. D) violet. E) all the same

Q: When white light goes from air into water, the color that refracts the most is A) red. B) orange. C) green. D) violet. E) all refract the same amount.

Q: Different colors of light travel at different speeds in a transparent medium. In a vacuum, different colors of light travel at A) different speeds. B) the same speed. C) decreased speed.

Q: Rainbows exist because light is A) reflected. B) refracted. C) both of these D) none of the above

Q: A primary rainbow is brighter than a secondary rainbow because A) sunlight reaching it is more intense. B) there is one less reflection inside the water drops. C) larger drops produce primary rainbows. D) the secondary bow is a dim reflection of the primary rainbow. E) none of the above

Q: The secondary rainbow is dimmer than the primary rainbow because A) its colors are inverted. B) it is larger, and its energy spreads across more area. C) it is farther from the viewer. D) it simply has much less energy than the primary bow. E) of a double reflection and refraction in the drops.

Q: A single raindrop illuminated by sunshine disperses A) a single color. B) either low, middle, or high frequency colors in most cases. C) all the colors just like a small prism does.

Q: Rainbows are not usually seen as complete circles because A) the ground is usually in the way. B) they are actually elliptical. C) they have no bottom part. D) raindrops are not perfectly round. E) rainbows are arched shaped.

Q: Light from inside a raindrop that exits into the air A) slows down. B) remains at speed c. C) speeds up. D) none of the above

Q: When light from the air enters a raindrop, the light A) slows down. B) remains at speed c. C) speeds up. D) none of the above

Q: When light from air passes through a prism, light of all frequencies A) slow down. B) remain at speed c. C) speed up. D) none of the above

Q: When white light is dispersed in a prism, the fastest light is A) red. B) orange. C) green. D) blue. E) same in all

Q: The colors dispersed by a prism are due to different light A) speeds inside the prism. B) directions inside the prism. C) energies inside the prism. D) none of the above

Q: Distant snow-covered hills appear yellowish due to the color of the A) atmosphere between the observer and the hills. B) selectively reflected light that reaches a distant observer. C) reflected light that survives scattering. D) sky that is reflected off the hills.

Q: Distant dark-colored hills appear blue due to the color of the A) atmosphere between the observer and the dark hills. B) selectively reflected light that reaches a distant observer. C) reflected light that survives scattering. D) sky that is reflected off the hills.

Q: Consider the appearance of an American flag submerged deep in water. The white stars and red stripes appear A) cyan and red. B) cyan and blue. C) red and black. D) cyan and black.

Q: If the atmosphere were about 40 times thicker, at noon the Sun would appear A) red-orange. B) orange-green. C) green-blue. D) blue-violet. E) none of the above

Q: If molecules in the sky scattered red-orange light strongly instead of blue light, sunsets would be A) orange. B) yellow. C) green. D) blue.

Q: If sunlight were green instead of white, the most comfortable color to wear on a cold day would be A) magenta. B) yellow. C) green. D) blue. E) violet.

Q: If sunlight were green instead of white, the most comfortable color to wear on a hot day would be A) magenta. B) yellow. C) green. D) blue. E) violet.

Q: The yellow clothes of a stage performer appear black when illuminated by light that is A) red. B) green. C) blue. D) all the above combined E) none of the above

Q: A blue object will appear black when illuminated with A) blue light. B) cyan light. C) yellow light. D) light. E) none of the above

Q: A sheet of red paper will look black when illuminated with A) red light. B) yellow light. C) magenta light. D) cyan light. E) none of the above

Q: A red crab crawling very deep in the water where sunlight is very dim appears A) red. B) orange. C) cyan. D) brown. E) black.

Q: The part of the electromagnetic spectrum most absorbed by water is A) infrared. B) lower frequencies of visible light. C) middle frequencies of visible light. D) higher frequencies of visible light. E) all of the above

Q: The greenish blue of water is evidence for the A) reflection of greenish-blue light. B) reflection of red light. C) absorption of greenish-blue light. D) absorption of red light. E) interaction between green and blue frequencies of light.

Q: The whiteness of clouds is due mainly to A) scattering. B) reflection. C) polarization. D) water prisms.

Q: An important feature of red sunsets is the A) scattering of lower frequencies by larger particles in the air. B) longer path of air through which sunlight travels. C) lower frequencies of light emitted late in the day by the Sun. D) absorption effects of the smaller particles in the air.

Q: Red sunsets are due to light of lower frequencies that A) is scattered from larger particles in the air. B) is refracted from larger particles in the air. C) is reflected by clouds and relatively large particles in the air. D) survive being scattered in the air. E) appear reddish orange to the eye.

Q: The sky is the deepest blue A) just before a rainstorm. B) during a rainstorm. C) just after a rainstorm. D) when the air is humid. E) just before sunset.

Q: A whitish sky is evidence that the atmosphere contains A) predominantly small particles. B) predominantly large particles. C) a mixture of particle sizes. D) pollutants.

Q: The sky is blue because air molecules in the sky act as tiny A) mirrors that reflect only blue light. B) resonators that scatter blue light. C) sources of white light. D) prisms. E) none of the above

Q: Which interacts more with light of relatively high frequencies? A) large particles B) small particles C) both the same

Q: Which interacts more with sounds of relatively high frequencies? A) large bells B) small bells C) both the same

Q: Humans see best in the yellow-green region of the spectrum. So the efficiency of sodium yellow-green lamps that illuminate highways is A) higher. B) lower. C) not affected.

Q: The inks used in printing the full-color photos in a common magazine are A) red, green, and blue. B) red, green, blue, and black. C) magenta, cyan, and yellow. D) magenta, cyan, yellow, and black. E) none of the above

Q: A mixture of cyan and yellow inks on a printed page appears A) orange. B) yellow. C) magenta. D) blue. E) green.

Q: Magenta light is a mixture of A) red and blue light. B) red and cyan light. C) red and yellow light. D) yellow and green light. E) none of the above

Q: The complementary color of blue is A) red. B) green. C) yellow. D) cyan. E) magenta.

Q: Complementary colors are two colors that A) share the same color scheme. B) are additive primary colors. C) are subtractive primary colors. D) produce white light when combined.

Q: A golf ball illuminate by only red light casts a colorless shadow. If instead it is also illuminated by a close-by green light source, the non-overlapping shadows will be A) green and red. B) cyan and magenta. C) white. D) none of the above