1.
Color depends on what characteristic of light?
Correct Answer
A. Its frequency
Explanation
The color of light depends on its frequency. Frequency refers to the number of complete cycles of a wave that occur in a second. Different frequencies of light correspond to different colors in the visible spectrum. For example, light with a high frequency appears blue or violet, while light with a low frequency appears red. Therefore, the frequency of light determines the color we perceive.
2.
When the frequency of light matches the natural frequency of molecules in a material, light is
Correct Answer
A. Absorbed.
Explanation
When the frequency of light matches the natural frequency of molecules in a material, light is absorbed. This is because the energy of the light waves is transferred to the molecules, causing them to vibrate or move to a higher energy state. This absorption of light can lead to various effects, such as heating of the material or triggering chemical reactions.
3.
The color of an opaque object is the same as the light that is
Correct Answer
C. Reflected.
Explanation
When light hits an opaque object, it is not transmitted through it, nor is it absorbed completely. Instead, the object reflects certain wavelengths of light, which are then detected by our eyes as color. Therefore, the correct answer is "reflected."
4.
What color light is transmitted by a piece of blue glass?
Correct Answer
C. Blue
Explanation
Blue glass transmits blue light because it selectively absorbs all other colors of light and only allows blue light to pass through. This is due to the molecular structure of the glass, which absorbs certain wavelengths of light and reflects or transmits others. Therefore, when light passes through a piece of blue glass, only the blue wavelengths are able to pass through, resulting in the transmitted light appearing blue.
5.
The brightest color emitted by the sun is
Correct Answer
C. Yellow-green.
Explanation
The sun emits light across a wide range of colors, but the brightest color it emits is yellow-green. This is because the sun's surface temperature is around 5,500 degrees Celsius, which corresponds to the peak of its blackbody radiation curve in the yellow-green part of the spectrum. This color is most dominant and visible to our eyes, making it the brightest color emitted by the sun.
6.
The solar radiation curve is
Correct Answer
C. A plot of brightness of sunlight versus its frequency.
Explanation
The solar radiation curve refers to a plot of the brightness of sunlight versus its frequency. This means that it shows how the brightness of sunlight changes as the frequency of the light waves varies. It does not represent the path taken by the sun or the colors of sunlight. It also does not show the relationship between light intensity and distance from the sun.
7.
Which will warm up quicker in sunlight?
Correct Answer
A. A piece of colored glass
Explanation
A piece of colored glass will warm up quicker in sunlight because colored objects absorb more light and heat compared to clear objects. The color of the glass determines which wavelengths of light it absorbs and reflects. Clear glass allows most of the light to pass through, while colored glass absorbs certain wavelengths, converting them into heat energy. Therefore, the colored glass will absorb more sunlight and warm up faster than the clear glass.
8.
Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in the
Correct Answer
B. Green glass.
Explanation
When light shines on a pane of green glass, the glass absorbs most of the light except for the green wavelength, which is reflected back. This absorption of light by the green glass causes it to heat up more compared to the clear glass, which allows more light to pass through without being absorbed. Therefore, the temperature will be higher in the green glass.
9.
The colored dots that make up the color on a TV screen are
Correct Answer
B. Red, blue, green.
Explanation
The correct answer is red, blue, green. This is because red, blue, and green are the primary colors of light used in additive color mixing. By combining different amounts of these three colors, all other colors can be created on a TV screen.
10.
If three primary colors of light are to shine on a white wall to produce a white spot, the primaries must be
Correct Answer
A. Additive.
Explanation
When three primary colors of light are combined additively, they create white light. This is because additive color mixing involves combining different wavelengths of light to produce a wider range of colors. In this case, the three primary colors of light would need to be combined in order to create a white spot on the white wall. Therefore, the correct answer is additive.
11.
Complementary colors are two colors that
Correct Answer
D. Produce white light when added together.
Explanation
Complementary colors are pairs of colors that, when combined, produce white light. This is because complementary colors are located opposite each other on the color wheel, and when they are mixed, they cancel out each other's wavelengths, resulting in white light. This phenomenon is known as color subtraction, where the colors subtract from each other to create white. Therefore, the correct answer is that complementary colors produce white light when added together.
12.
The complementary color of blue is
Correct Answer
C. Yellow.
Explanation
The complementary color of blue is yellow because complementary colors are pairs of colors that, when combined, create a neutral color (such as white or gray). Blue and yellow are complementary colors because they are located opposite each other on the color wheel. When blue and yellow are mixed together, they create a neutral gray color.
13.
Magenta light is really a mixture of
Correct Answer
A. Red and blue light.
Explanation
Magenta light is perceived as a single color, but it is actually a mixture of red and blue light. When red and blue light are combined, they create the sensation of magenta. This is because magenta is not a spectral color and cannot be created by a single wavelength of light. Instead, it is created by stimulating both the red and blue cones in our eyes, which results in the perception of magenta. Therefore, the correct answer is red and blue light.
14.
Colors seen on TV results from color
Correct Answer
A. Addition.
Explanation
The colors seen on TV result from color addition. This means that different colors are combined to create the desired hues. In TV screens, three primary colors (red, green, and blue) are used to produce a wide range of colors by varying their intensities. By adding these colors together in different proportions, the TV is able to display a full spectrum of colors. This process is known as additive color mixing and is the reason behind the vibrant and diverse colors we see on TV screens.
15.
Colors seen on the cover of our physics book result from color
Correct Answer
B. Subtraction.
Explanation
The colors seen on the cover of our physics book result from color subtraction. This means that the colors we perceive are the result of certain wavelengths of light being absorbed or subtracted by the pigments on the cover, while the remaining wavelengths are reflected and reach our eyes, creating the perception of color. This is different from color addition, where colors are produced by combining different wavelengths of light.
16.
How many colors of ink are used to print full-color pictures?
Correct Answer
C. Three plus black
Explanation
Full-color pictures are typically printed using a combination of cyan, magenta, yellow, and black inks. These four colors, also known as CMYK, are used to create a wide range of colors and shades. In addition to these three primary colors, black ink is added to enhance contrast and depth in the image. Therefore, the correct answer is "three plus black," indicating that three colors (cyan, magenta, and yellow) are used along with black ink to print full-color pictures.
17.
Different colors of light correspond to different light
Correct Answer
D. Frequencies.
Explanation
Different colors of light correspond to different frequencies. This is because color is determined by the wavelength of light, and frequency and wavelength are inversely proportional. Therefore, light with a shorter wavelength (such as blue or violet) has a higher frequency, while light with a longer wavelength (such as red or orange) has a lower frequency. This is why we see different colors in a rainbow or when light passes through a prism.
18.
A mixture of red and green pigments appears
Correct Answer
E. Blackish brown.
Explanation
When red and green pigments are mixed together, they create a color that is a combination of the two. In this case, the mixture of red and green pigments would result in a color that is a dark brown, almost blackish in appearance. This is because red and green are complementary colors, meaning they are opposite each other on the color wheel. When complementary colors are mixed together, they tend to neutralize each other and create a darker, more muted color.
19.
A mixture of cyan and yellow pigments appears
Correct Answer
B. Green.
Explanation
When cyan and yellow pigments are mixed together, they absorb certain wavelengths of light and reflect others. Cyan pigment absorbs red light, while yellow pigment absorbs blue light. As a result, when these two pigments are mixed, they absorb both red and blue light, leaving green light to be reflected. Therefore, the mixture of cyan and yellow pigments appears green.
20.
Look at a full-color picture in a magazine with a magnifying glass and you'll see that the inks used are
Correct Answer
D. Magenta, cyan, yellow, and black.
21.
Which interacts more with sounds of relatively high frequencies?
Correct Answer
B. Small bells
Explanation
Small bells interact more with sounds of relatively high frequencies because they have smaller dimensions and a higher resonant frequency. The smaller size of the bell allows it to vibrate at a higher frequency when struck, producing higher-pitched sounds. In contrast, large bells have larger dimensions and a lower resonant frequency, causing them to interact more with sounds of lower frequencies.
22.
Which interacts more with light of relatively high frequencies?
Correct Answer
B. Small particles
Explanation
Small particles interact more with light of relatively high frequencies because of a phenomenon called Rayleigh scattering. When light interacts with small particles, such as molecules or tiny particles, the wavelength of the light becomes comparable to the size of the particles. This causes the light to scatter in all directions, with shorter wavelengths (higher frequencies) being scattered more efficiently. As a result, small particles tend to scatter light of higher frequencies more effectively than large particles.
23.
The sky is blue because air molecules in the sky act as tiny
Correct Answer
B. Resonators which scatter blue light.
Explanation
Air molecules in the sky act as tiny resonators which scatter blue light. When sunlight passes through the Earth's atmosphere, it interacts with the air molecules. The shorter blue wavelengths of light are scattered more than the longer wavelengths, such as red and yellow. This scattering process is known as Rayleigh scattering, and it is responsible for the blue color of the sky. The air molecules act as resonators, absorbing and re-emitting the blue light in all directions, resulting in the blue appearance of the sky.
24.
A whitish sky is evidence that the atmosphere contains
Correct Answer
C. A mixture of particle sizes.
Explanation
A whitish sky is evidence that the atmosphere contains a mixture of particle sizes. This is because when the atmosphere contains particles of different sizes, they scatter sunlight in different ways. The scattering of sunlight by small particles causes the sky to appear blue, while the scattering by larger particles can cause the sky to appear white or gray. Therefore, a whitish sky suggests the presence of both small and large particles in the atmosphere.
25.
Sunsets are red, blue jays are blue; the reason's the same:
Correct Answer
A. Scattered sunlight – nothing new.
Explanation
The given answer, "scattered sunlight - nothing new," is the correct explanation for the phenomenon described in the passage. Sunsets appear red because the light from the sun is scattered by particles in the atmosphere, causing shorter blue and green wavelengths to scatter more and longer red wavelengths to dominate. Similarly, blue jays appear blue because their feathers contain pigments that reflect blue light. In both cases, the color is a result of light scattering, which is a well-known phenomenon. The mention of aerosols and goo suggests that there may be additional factors contributing to the scattering, but the main reason is still scattered sunlight.
26.
The sky is the deepest blue
Correct Answer
C. Just after a rainstorm.
Explanation
The correct answer is just after a rainstorm. This is because after a rainstorm, the sky tends to clear up and the clouds disperse, allowing more sunlight to pass through. As a result, the sky appears deep blue. During a rainstorm, the sky is usually covered with dark clouds, and just before a rainstorm, the sky may appear gray or overcast. When the air is humid, the sky may appear hazy or have a lighter shade of blue. Just before sunset, the sky often takes on warm colors such as orange or pink, but not necessarily the deepest blue.
27.
Red sunsets are due to lower frequencies of light that
Correct Answer
D. Survive being scattered in the air.
Explanation
Red sunsets occur because the lower frequencies of light, such as red and orange, are able to survive being scattered in the air. When the sun is low on the horizon, its light has to pass through a larger portion of the Earth's atmosphere, which scatters the shorter wavelengths of light, such as blue and green. However, the longer wavelengths, like red and orange, are able to pass through the atmosphere without being scattered as much, resulting in a red sunset.
28.
The sun is more likely to appear red at sunset than in the middle of the day as a result of the
Correct Answer
B. Longer path of air through which sunlight travels.
Explanation
The sun is more likely to appear red at sunset than in the middle of the day because the longer path of air through which sunlight travels at sunset causes the shorter wavelengths of light (blue and green) to scatter more, leaving behind the longer wavelengths (red and orange) which are more visible to our eyes.
29.
A variety of sunset colors is evidence for a variety of
Correct Answer
C. AtmospHeric particles.
Explanation
The variety of sunset colors is evidence for a variety of atmospheric particles. When sunlight passes through the Earth's atmosphere during sunset, it scatters off the particles present in the atmosphere. The scattering process causes the different colors of light to separate, resulting in the variety of colors observed during a sunset. Therefore, the presence of different atmospheric particles leads to the variety of sunset colors.
30.
The whiteness of clouds is evidence in the clouds for a variety of
Correct Answer
A. Particle sizes.
Explanation
The whiteness of clouds is evidence for a variety of particle sizes. Clouds appear white because they contain a large number of tiny water droplets or ice crystals. These particles scatter sunlight in all directions, causing the cloud to appear white. The size of the particles in the cloud determines how they scatter light, with smaller particles scattering shorter wavelengths (blue light) more effectively, giving the cloud a white appearance. Therefore, the presence of different particle sizes in the cloud contributes to its whiteness.
31.
The greenish blue of water is evidence for the
Correct Answer
D. Absorption of red light.
Explanation
The greenish blue color of water is evidence for the absorption of red light. When white light, which is made up of all the colors of the visible spectrum, passes through water, the water molecules selectively absorb certain colors of light. In this case, the water molecules absorb the red light, while allowing the greenish-blue light to be transmitted or reflected, resulting in the observed color of water.
32.
The part of the electromagnetic spectrum most absorbed by water is
Correct Answer
A. Infrared.
Explanation
Water molecules have a specific vibrational frequency that corresponds to the infrared region of the electromagnetic spectrum. When infrared radiation interacts with water, it causes the water molecules to vibrate and absorb the energy. This absorption of infrared radiation by water is what makes it the part of the electromagnetic spectrum most absorbed by water.
33.
A red crab very deep in water, where sunlight is dim, appears
Correct Answer
E. No color – black.
Explanation
In deep water where sunlight is dim, there is not enough light for colors to be perceived. Therefore, the red crab would appear black because it is not reflecting any light and absorbing all the colors.
34.
A sheet of red paper will look black when illuminated with
Correct Answer
C. Magenta light.
Explanation
When a sheet of red paper is illuminated with magenta light, the paper will appear black. This is because magenta light contains both red and blue wavelengths, but no green wavelength. Since red paper reflects red light and absorbs blue and green light, when illuminated with magenta light, the red light is absorbed and only the blue light is reflected. As a result, the paper appears black.
35.
A blue object will appear black when illuminated with
Correct Answer
C. Yellow light.
Explanation
When a blue object is illuminated with yellow light, the blue object will appear black. This is because yellow light is the complementary color of blue. When these two colors are combined, they cancel each other out, resulting in the perception of black.
36.
If sunlight were green instead of white, the most comfortable color to wear on a hot day would be
Correct Answer
C. Green.
Explanation
If sunlight were green instead of white, the most comfortable color to wear on a hot day would be green. This is because green is the complementary color to red, which is the color that is absorbed the most by our skin. Since green would be the dominant color in the sunlight, wearing green would help to reflect and deflect the green light, reducing the amount of heat absorbed by the body and making it more comfortable on a hot day.
37.
If sunlight were green instead of white, the most comfortable color to wear on a cold day would be
Correct Answer
A. Magenta.
Explanation
If sunlight were green instead of white, the most comfortable color to wear on a cold day would be magenta. This is because magenta is a warm color that contains red and blue, which can help to absorb and retain heat. Wearing magenta would help to keep the body warm in the absence of the usual warmth provided by white sunlight.
38.
Distant dark colored hills appear blue because that is the color of the
Correct Answer
A. AtmospHere between the observer and the hills.
Explanation
Distant dark colored hills appear blue because that is the color of the atmosphere between the observer and the hills. When light from the hills reaches the observer, it has to pass through the atmosphere. The atmosphere scatters shorter wavelengths of light (blue) more than longer wavelengths (red). As a result, more blue light is scattered towards the observer, making the hills appear blue.
39.
Distant snow covered hills appear yellowish because that is the color of the
Correct Answer
C. Reflected light that survives scattering.
Explanation
When light passes through the atmosphere, it gets scattered by the molecules and particles present in the air. This scattering causes the blue light to be scattered more than the other colors of light, making the sky appear blue. However, some of the light that is scattered by the atmosphere and reaches the distant observer is not scattered as much and retains its original color. In the case of distant snow-covered hills, the scattered blue light is mostly absorbed or scattered away, leaving behind the other colors of light, particularly the longer wavelength colors like yellow. Therefore, the hills appear yellowish to the observer because it is the reflected light that survives scattering.
40.
If molecules in the sky scattered orange light instead of blue light, sunsets would be colored
Correct Answer
D. Blue.
Explanation
If molecules in the sky scattered orange light instead of blue light, sunsets would be colored blue. This is because during sunset, the sunlight has to pass through a larger portion of the Earth's atmosphere, causing more scattering of shorter wavelength light. If the molecules in the sky scattered orange light, which has a longer wavelength than blue light, then the blue light would be filtered out and the remaining light would appear orange. Therefore, the correct answer is blue.
41.
If the atmosphere were about 40 times thicker, at noon the sun would appear
Correct Answer
A. Red-orange.
Explanation
If the atmosphere were about 40 times thicker, the increased density of air molecules would scatter more of the shorter wavelength blue and green light. This would make the sunlight that reaches our eyes appear more red and orange in color. Therefore, at noon the sun would appear red-orange.
42.
The atmosphere of Jupiter is more than 1000 km thick. From the planet's surface, the noon-day sun would appear
Correct Answer
D. None of these
Explanation
The atmosphere of Jupiter is composed mainly of hydrogen and helium, which scatter sunlight in different ways compared to Earth's atmosphere. Therefore, the noon-day sun would not appear white, faintly white, or not at all as it does on Earth. Instead, it would appear as different colors due to the scattering of sunlight by Jupiter's atmospheric gases.
43.
On a planet where atmospheric gases are red, distant dark colored hills would look
Correct Answer
D. Reddish.
Explanation
On a planet where atmospheric gases are red, the distant dark colored hills would appear reddish. This is because the atmosphere of the planet would cause the light to be scattered and absorbed in such a way that the hills would be perceived as having a reddish hue. The color of the atmosphere affects the way we perceive the colors of objects in the distance, and in this case, the red atmospheric gases would make the hills appear reddish.
44.
On a planet where atmospheric gases are yellow, distant snow covered hills would look
Correct Answer
A. Bluish.
Explanation
On a planet where atmospheric gases are yellow, distant snow-covered hills would look bluish. This is because when sunlight passes through the yellow atmosphere, the blue light is scattered more than other colors due to its shorter wavelength. As a result, the scattered blue light reaches our eyes, making the distant snow-covered hills appear bluish.
45.
The redness of the lunar eclipse is evidence for the
Correct Answer
A. Refraction of sunsets and sunrises all around the world.
Explanation
The redness of the lunar eclipse is evidence for the refraction of sunsets and sunrises all around the world. During a lunar eclipse, the Earth blocks direct sunlight from reaching the moon. However, some sunlight still manages to reach the moon by bending or refracting around the Earth's atmosphere. This refracted sunlight passes through the Earth's atmosphere, which scatters shorter wavelengths of light and allows longer wavelengths (such as red) to reach the moon. As a result, the moon appears red during a lunar eclipse, providing evidence for the refraction of sunsets and sunrises worldwide.