The Light Test consists of 23 questions. Correct answers will be provided after your answers have been submitted. If they are available, possible solutions can be accessed by clicking an additional link at the bottom of the answer, which will open a problem solution screen. If you bring up such a solution screen be sure to close it by clicking the button in the upper left corner or upper right corner.
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1 | |
An image that does not have light rays coming from the image, but is the result of your brain's interpretations of light rays is called a |
| | A) | real image. |
| | B) | imagined image. |
| | C) | virtual image. |
| | D) | phony image. |
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2 | |
Light traveling at some angle as it moves from water into the air is refracted away from the normal as it enters the air, so the fish you see under water is actually |
| | A) | above the refracted image. |
| | B) | below the refracted image. |
| | C) | beside the refracted image. |
| | D) | in the same place as the refracted image. |
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3 | |
When viewed straight down (90° to the surface), a fish under water is |
| | A) | above the image (away from you). |
| | B) | below the image (closer to you). |
| | C) | beside the image. |
| | D) | in the same place as the image. |
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4 | |
Any part of the electromagnetic spectrum, including the colors of visible light, can be measured in units of |
| | A) | wavelength. |
| | B) | frequency. |
| | C) | energy. |
| | D) | any of these. |
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5 | |
The ratio of the speed of light in a vacuum to the speed of light in some transparent materials is called |
| | A) | the critical angle. |
| | B) | total internal reflection. |
| | C) | the law of reflection. |
| | D) | the index of refraction. |
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6 | |
Which characteristic of waves of visible light is most similar to waves of microwaves? |
| | A) | speed |
| | B) | wavelength |
| | C) | frequency |
| | D) | amplitude |
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7 | |
The shortest of all the radio waves is the |
| | A) | FM broadcast |
| | B) | AM broadcast |
| | C) | microwave |
| | D) | shortwave |
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8 | |
Which of the following can only be explained by a wave model of light? |
| | A) | reflection |
| | B) | refraction |
| | C) | interference |
| | D) | photoelectric effect |
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9 | |
The sky appears to be blue when the sun is high in the sky because |
| | A) | blue is the color of air, water, and other fluids in large amounts. |
| | B) | red light is scattered more than blue light. |
| | C) | blue light is scattered more than the other colors. |
| | D) | none of the above |
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10 | |
Max Planck found wave theory-shattering evidence that light of a certain color emitted from vibrating molecules would have |
| | A) | a continuous range of energy amounts. |
| | B) | a variable and unpredictable energy amount. |
| | C) | a fixed amount of energy. |
| | D) | no energy at all. |
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11 | |
When you see a rainbow, you know for sure that |
| | A) | the sun must be directly, or almost directly overhead. |
| | B) | that rain is falling between where you are and where the sun is located at the time. |
| | C) | you are between the sun in one direction and a rainshower in the other direction. |
| | D) | that the sun, you, and the location of the rainfall must be at right angles. |
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12 | |
An optically formed duplicate of an object that has light actually coming from the duplicate is |
| | A) | a real image. |
| | B) | found only in science fiction. |
| | C) | possible only if a laser is used. |
| | D) | a virtual image. |
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13 | |
If you want to see your whole image in a mirror, from head to foot, you will need a flat mirror that is |
| | A) | the same height as you. |
| | B) | at least half as tall as you are. |
| | C) | is twice your height. |
| | D) | the same height as a door. |
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14 | |
The virtual image seen in a flat mirror is |
| | A) | inside-out. |
| | B) | up-side-down. |
| | C) | left and right reversed. |
| | D) | all of these. |
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15 | |
A slide projector uses a convex lens system, with the film between one and two focal lengths of the lens. Why is the image not inverted? |
| | A) | It is upright because it is a real image. |
| | B) | It is upright because the film is put in upside down. |
| | C) | It is upright because it is a virtual image. |
| | D) | None of the above. |
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16 | |
If the Sun is 1.50 X 108 km from the Earth, how many minutes are required for sunlight to reach the Earth? |
| | A) | 0.0 min |
| | B) | 1,440 min |
| | C) | 500.0 min |
| | D) | 8.3 min |
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17 | |
How many hours are required for a radio signal from a space probe near the planet Pluto, 6.00 X 109 km away to reach the Earth? |
| | A) | 0.134 hr |
| | B) | 8.33 min |
| | C) | 5.56 hr |
| | D) | 0.00 s |
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18 | |
A right ray is reflected from a mirror with an angle 10° to the normal. What was the angle of incidence? |
| | A) | 80° |
| | B) | 10° |
| | C) | 35° |
| | D) | 170° |
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19 | |
Light travels through a transparent substance at 2.20 X 108 m/s. What is the substance? |
| | A) | ethyl alcohol |
| | B) | water |
| | C) | a vacuum |
| | D) | solid ice |
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20 | |
What is the speed of light in a diamond? |
| | A) | 3.020 X 108 m/s |
| | B) | 7.26 X 108 m/s |
| | C) | 1.24 X 108 m/s |
| | D) | none of the above. |
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21 | |
What is the energy of a photon of red light with a frequency of 4.00 X 1014 Hz? |
| | A) | 1.66 X 10-48 J |
| | B) | 2.65 X 10-19 J |
| | C) | 6.63 X 10-34 J |
| | D) | 4.00 X 1014 J |
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22 | |
A light wave has a frequency of 4.90 X 1014 Hz. What color would you observe? |
| | A) | orange |
| | B) | blue |
| | C) | green |
| | D) | yellow |
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23 | |
What is the energy of a microwave photon of wavelength 1.00 mm? |
| | A) | 3.00 X 1011 J |
| | B) | 1.99 X 10-22 J |
| | C) | 2.21 X 10-45 J |
| | D) | 1.00 J |
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