Quiz 11: Light

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.

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

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.

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

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

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.

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

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

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

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.

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

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

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

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

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

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

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

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

A wave with a long wavelength has a relatively A)low frequency. B)high frequency. C)both of these D)neither

Relative to radio waves,the velocity of visible light waves in a vacuum is A)less. B)more. C)the same.

Relative to ultraviolet waves,the wavelength of infrared waves is A)shorter. B)longer. C)the same.

Your friend says that any radio wave travels appreciably faster than any sound wave. A)agree with your friend unconditionally B)agree with your friend for most common cases C)disagree with your friend D)find a new friend

Radio waves travel A)always much faster than sound waves. B)usually at the same speed as sound waves. C)slower,on average,than sound waves. D)at a speed that depends on frequency.

An electron vibrating to and fro 1000 times per second generates an electromagnetic wave having a A)period of 1000 s. B)speed of 1000 m/s. C)wavelength of 1000 m. D)frequency of 1000 Hz.

If a light signal and a radio signal were emitted simultaneously from Alpha Centauri,the first to reach Earth would be the A)radio signal. B)light signal. C)both the same time

If a light signal and a radio signal were emitted simultaneously from the Moon,the first signal to reach Earth would be A)radio. B)light. C)both of these D)none of the above

The distance between Earth and the Moon is 3.84 10⁸ m.A pulse of laser light aimed at the Moon that bounces back to Earth undergoes a round-trip time of about A)zero seconds. B)less than 1 second. C)two and a half seconds. D)three seconds.

Relative to its average speed in air,the average speed of a beam of light in glass is A)more. B)the same. C)less.

Electrons in glass have a natural frequency in the A)infrared region of the spectrum. B)visible region of the spectrum. C)ultraviolet region of the spectrum.

When ultraviolet light is incident upon glass,most atoms in the glass A)resonate. B)pass the light energy along practically undiminished. C)freely absorb and reemit most of the ultraviolet light.

Visible light that shines on a pane of transparent glass A)is mostly reflected. B)produces a chain of absorptions and re-emissions through the glass. C)mostly transforms to thermal energy.

When visible light is incident upon transparent glass,most atoms in the glass A)are forced into vibration. B)resonate. C)convert the light energy into thermal energy.

Non-reflected ultraviolet light that shines on a pane of transparent glass A)produces a chain of absorptions and re-emissions through the glass. B)transforms to thermal energy. C)is mostly reflected.

Consider light energy that is momentarily absorbed in glass and then reemitted.Relative to the absorbed light,the frequency of the reemitted light is A)less. B)the same. C)more.

Compared with the speed of light in a vacuum,the speed of light in the empty space between molecules in glass is A)more. B)the same. C)less.

Infrared waves are often called heat waves because they A)emanate from relatively hot sources. B)consist of frequencies lower than those of visible light. C)induce resonance of molecules in the skin that becomes thermal energy. D)are absorbed rather than reflected by the skin. E)are the predominant waves emitted by the Sun.

Compared with the photons of light that shines on glass,the emerging photons are A)the same photons. B)different though identical. C)a mixture of being the same and different.

Metals are shiny because A)they reflect 100% of incident light. B)they are poor absorbers of light. C)loose electrons vibrate to the oscillations of any incident light. D)none of the above

Materials generally become warmer when light is A)absorbed by them. B)reflected by them. C)transmitted by them. D)all of the above E)none of the above

Glass is transparent to light of frequencies that A)match its natural frequencies. B)are below its natural frequencies. C)both of these D)none of the above

Glass is opaque to light with wave frequencies that A)match its natural frequencies. B)are below its natural frequencies. C)both of these D)none of the above

Which becomes warmer in sunlight,sunglasses or clear reading glasses? A)sunglasses. B)reading glasses. C)both of these D)none of the above

Which will warm up quicker in sunlight? A)a piece of colored glass B)a piece of clear glass C)both the same

Light shines on a pane of green glass and a pane of clear glass.The temperature will be higher in the A)clear glass. B)green glass. C)neither

The reason that a surface appears darker when wet has to do with A)the darkness of liquids. B)conversion of light to lower frequencies. C)absorption of multiply-reflecting light inside the wet region.

The image seen in a plane mirror is due to A)specular reflection. B)diffuse reflection. C)both of these D)neither of these

When you read from a printed page,you're seeing reflected light that is A)specular. B)diffuse. C)both of these D)neither of these

According to the law of reflection,the incident ray,reflected ray,and normal between them A)lie in the same plane. B)may or may not lie in the same plane. C)lie in planes that are perpendicular to one another.

Object and image for a plane mirror lie A)along the same plane. B)equal distances from the mirror. C)at right angles to each other. D)all of the above E)none of the above

The amount of light reflected from the front surface of common window glass is about A)4%. B)8%. C)40%. D)92%. E)96%.

When light reflects from a polished surface,there is a change in its A)frequency. B)wavelength. C)speed. D)all of the above E)none of the above

The inversion of Marjorie's image in a plane mirror is actually an inversion of A)left and right. B)up and down. C)front and back. D)all of the above

For a curved mirror,the law of reflection holds for A)the mirror as with a plane mirror. B)tiny segments that act as plane surfaces. C)both convex and concave mirrors. D)only convex mirrors.

If you walk toward a mirror at a certain speed,the relative speed between you and your image is A)half your speed. B)your speed. C)twice your speed. D)none of the above

Diffuse reflection occurs when the size of surface irregularities is A)small compared to the wavelength of the light used. B)large compared to the wavelength of the light used. C)either

Compared to the wavelength of incident light,diffuse reflection occurs when the size of surface irregularities is A)smaller. B)larger. C)about the same.

A rough surface for infrared waves may be polished for A)radio waves. B)light waves. C)both of these D)neither

The shortest plane mirror in which you can see your entire image is A)half your height. B)3/4 your height. C)1/3 your height. D)equal to your height. E)dependent on your distance from the mirror.

To see his full height,Blinky Bill who is 1.0 meter tall needs a mirror that is at least A)0.33 m tall. B)0.50 m tall. C)0.75 m tall. D)1 m tall. E)depends on distance from the mirror.

In looking at yourself in a steamy mirror you wipe just enough moisture away to barely see a full view of your face.If you move back from the mirror you'll see A)a bit more of your face. B)a bit less of your face. C)the same amount of your face.

When you look at yourself in a pocket mirror,and then hold the mirror farther away,you see A)more of yourself. B)less of yourself. C)the same amount of yourself.

A diver shines light up to the surface of a smooth pond at a 10° angle to the normal.Some light passes into the air above,and the part that reflects back into the water makes an angle to the normal of A)less than 10°. B)10°. C)more than 10°.

Standing at the shore of a still lake,the reflected view of scenery on the far side of the lake is the view you would see if you were upside down with your eye in the line of sight A)where it presently is. B)at the surface of the water where the light reflects. C)directly beneath you,as far below water level as you are above. D)close to the distant shore. E)none of the above

When a mirror with a fixed beam on it is rotated through a certain angle,the reflected beam is rotated through an angle A)equal to the angle of rotation. B)twice as much. C)four times as much. D)none of the above

The Moon's reflected image in a lake often appears as a vertical column when the water is A)perfectly still. B)slightly rough. C)very rough,churning with waves.

Ninety-five percent of light incident on a mirror is reflected.How much light is reflected from three mirrors in succession? A)81% B)86% C)90% D)95%

Refraction occurs when light passing from one medium to another A)changes frequency. B)changes speed. C)loses energy. D)reflects inward.

Refraction results from changes in light's A)frequency. B)incident angles. C)speed. D)all of the above E)none of the above

Light changes direction when traveling from air into glass due to changes in light's A)intensity. B)wavelength. C)frequency. D)velocity. E)amplitude.

A beam of light emerges from water into air at an angle bent A)towards the normal B)away from the normal. C)in a direction parallel to the normal. D)in a direction perpendicular to the normal. E)not at all.

When a light beam emerges from water into air,the average light speed A)increases. B)decreases. C)remains the same.

Refraction causes the bottom of a swimming pool to appear A)deeper. B)more shallow. C)neither

Because of refraction,a person standing waist deep in a swimming pool appears to have A)shorter legs. B)longer legs. C)thinner legs. D)none of the above

Because of refraction a fish in the water appears A)nearer the surface. B)deeper in the water. C)at its actual depth.

If you wish to spear a fish with a regular spear,you should compensate for refraction and throw your spear A)directly at the sighted fish. B)above the sighted fish. C)below the sighted fish.

If you wish to spear a red fish with a red laser beam,you should compensate for refraction and aim your laser A)directly at the sighted fish. B)above the sighted fish. C)below the sighted fish.

If you wish to spear a small blue fish with a red laser beam,you should compensate for refraction and aim your laser A)directly at the sighted fish. B)above the sighted fish. C)below the sighted fish.

If you wish to send a beam of laser light from Earth to a space station above the atmosphere near the horizon,aim your laser A)above your line of sight. B)below your line of sight. C)along your line of sight.

When light is refracted,there is a change in its A)frequency. B)wavelength. C)both of these D)neither

Light travels faster in A)warm air. B)cool air. C)a vacuum.

Light travels faster in A)thin air. B)dense air. C)same in each.

A mirage is a result of atmospheric A)reflection. B)refraction. C)scattering. D)dispersion. E)aberrations.

Because of refraction,the Sun near sunset appears A)higher in the sky. B)lower in the sky. C)farther away.

Atmospheric refraction makes the daylight hours A)longer. B)shorter. C)neither

Sometimes on a hot day a distant dry street appears wet,which is due to A)water from a previous rainfall. B)reflection of the sky from the street. C)refracted sky light.

A distant palm tree on a hot dry day that often appears to be reflected from water is A)due to light refracted upward as it grazes the hot surface. B)the inverse of a mirage. C)evidence that light travels in straight lines.

The twinkling of stars is a result of atmospheric A)reflection. B)refraction. C)scattering. D)dispersion. E)aberrations.

The color of an object depends on the colors of A)the light that illuminates them. B)molecules that comprise them. C)the foreground.

The white light from the Sun is a A)compliment of the surrounding blue sky. B)composite of light of all the visible frequencies. C)mixture of selected frequencies of light.

The black fur of a black-and-white bunny is due to light A)absorption. B)reflection. C)refraction. D)scattering.

A pane of red glass transmits primarily A)red light. B)the complementary color of red light. C)all colors of light.

The different colors of the spectrum A)are sharply divided. B)blend from one to another. C)differ from the colors of a rainbow.

The brightest color emitted by the Sun is A)red. B)yellow-green. C)blue. D)all the same

The color to which human eyes are most sensitive is A)red. B)yellow-green. C)blue. D)all the same

Which has the highest frequency? A)red light. B)green light. C)blue light. D)all the same

Different colors of light correspond to different light A)velocities. B)intensities. C)polarities. D)frequencies. E)none of the above

The color of an opaque object is the same as the light that is A)transmitted. B)absorbed. C)reflected. D)all of the above E)none of the above

The solar radiation curve is a graph of A)colors of sunlight versus their frequencies. B)colors of sunlight versus their wavelengths. C)the path of the Sun about Earth. D)brightness versus frequency. E)intensity versus distance from the Sun.

The three colors that comprise the image on a TV screen are A)red,blue,and yellow. B)red,blue,and green. C)yellow,blue,and green. D)magenta,cyan,and yellow. E)red,green,and yellow.

Colors seen on TV result from color A)addition. B)subtraction. C)either of these D)none of the above

Colors seen on the cover of our paper-bound physical science text book result from color A)addition. B)subtraction. C)either D)neither

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

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.

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

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

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

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

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.

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

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

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

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.

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.

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.

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.

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

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.

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

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.

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

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

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

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.

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.

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.

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

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.

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.

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.

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

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

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

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

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

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.

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.

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.

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

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

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.

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.

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

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

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

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

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

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

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.

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

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

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

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.

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%

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%.

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

Why is ultraviolet light not transmitted by glass?

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?

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

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?

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?

Explain why the sky is blue.

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

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