Chapter 28: Reflection And Refraction

87 Questions | Total Attempts: 265

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Chapter 28: Reflection And Refraction

Questions and Answers
  • 1. 
    Light is emitted when
    • A. 

      Electron clouds of atoms are forced into oscillation.

    • B. 

      Atomic nuclei are made to vibrate.

    • C. 

      Electromagnetic waves emanate from matter.

    • D. 

      High-frequency sound waves strike matter.

  • 2. 
    Light will almost always travel from one place to another along a path of least
    • A. 

      Distance.

    • B. 

      Time.

    • C. 

      Effort.

    • D. 

      Expense.

    • E. 

      Complication.

  • 3. 
    The incident light ray, the reflected light ray, and the 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.

  • 4. 
    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 these

  • 5. 
    The amount of light reflected from the front surface of a common windowpane is about
    • A. 

      4 percent.

    • B. 

      8 percent.

    • C. 

      40 percent.

    • D. 

      92 percent.

    • E. 

      96 percent.

  • 6. 
    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. 

      Microscopic.

  • 7. 
    A surface that is considered rough for infrared waves may be polished for
    • A. 

      Radio waves.

    • B. 

      Light waves.

    • C. 

      Both of these

    • D. 

      None of these

  • 8. 
    When light reflects from a surface, there is a change in its
    • A. 

      Frequency.

    • B. 

      Wavelength.

    • C. 

      Speed.

    • D. 

      All of these

    • E. 

      None of these

  • 9. 
    If you walk towards 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 these

  • 10. 
    The shortest plane mirror in which you can see your entire image is
    • A. 

      Half your height.

    • B. 

      About 3/4 your height.

    • C. 

      About 1/3 your height.

    • D. 

      Equal to your height.

    • E. 

      Dependent on your distance from the mirror.

  • 11. 
    To see his full height, a boy that is 1 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 how far the mirror is from the boy

  • 12. 
    You wish to photograph the image of your little sister, who is standing 2 meters from a plane mirror. Holding the camera beside her head, you should set the distance for
    • A. 

      1 meter.

    • B. 

      2 meters.

    • C. 

      3 meters.

    • D. 

      4 meters.

    • E. 

      None of these

  • 13. 
    A diver shines light up to the surface of a smooth pond at a 10-degree 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 degrees.

    • B. 

      10 degrees.

    • C. 

      More than 10 degrees.

  • 14. 
    A yellow-white candle flame reflected from a piece of red glass shows two images; one from each surface.
    • A. 

      Both images are yellow-white.

    • B. 

      One image is yellow-white and the other red.

    • C. 

      Both images are red.

    • D. 

      Both images are reddish yellow.

  • 15. 
    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.

  • 16. 
    It is difficult to see the roadway in front of you when you are driving on a rainy night mainly because
    • A. 

      Light scatters from raindrops and cuts down the light to reach your eyes.

    • B. 

      Of added condensation on the inner surface of the windshield.

    • C. 

      The film of water on your windshield provides an additional reflecting surface.

    • D. 

      The film of water on the roadway makes the road less diffuse.

    • E. 

      None of these

  • 17. 
    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 already 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 these

  • 18. 
    When a mirror with a fixed beam on it is rotated through a certain angle, the reflected beam is rotated through an angle that is
    • A. 

      Equal to the angle of rotation.

    • B. 

      Twice as large.

    • C. 

      Four times as large.

    • D. 

      None of these

  • 19. 
    The inversion of your image in a plane mirror is actually an inversion of
    • A. 

      Left-right.

    • B. 

      Up-down.

    • C. 

      Front-back.

    • D. 

      All of these

  • 20. 
    Reflected light from the moon 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.

  • 21. 
    Ninety-five percent of light incident on a mirror is reflected. How much light is reflected when three of these mirrors are arranged so light reflects from one after the other?
    • A. 

      81%

    • B. 

      85%

    • C. 

      86%

    • D. 

      90%

    • E. 

      95%

  • 22. 
    Two plane mirrors are at right angles to each other. A coin placed near the mirrors has at most
    • A. 

      2 images.

    • B. 

      3 images.

    • C. 

      4 images.

    • D. 

      More than 4 images.

  • 23. 
    As a light ray enters or exits a water-air interface at an angle of 15 degrees with the normal, it
    • A. 

      Always bends toward the normal.

    • B. 

      Always bends away from the normal.

    • C. 

      Sometimes bends towards the normal.

    • D. 

      Does not bend.

  • 24. 
    When light passes through an ordinary window pane, its angle of emergence is
    • A. 

      Usually less than its angle of incidence.

    • B. 

      Always less than its angle of incidence.

    • C. 

      The same as its angle of incidence.

    • D. 

      Usually more than its angle of incidence.

    • E. 

      Always more than its angle of incidence.

  • 25. 
    Light travels fastest in
    • A. 

      Warm air.

    • B. 

      Cool air.

    • C. 

      A vacuum.

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