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Homework Help: About aerial dish used in communication

  1. Jun 8, 2004 #1
    1. What is the function of the dish?
    Ans: It is to focus the weak signals so that to intensify them.

    2. What wave property is suitable to describe the phenomenon happened in the dish?
    Ans: Reflection.

    3. If an antenna is to be placed in front of the dish, where it should be placed to get the strongest signal?
    Ans: It should be placed at the principle focus of the dish.

    4. If the dish diameter is larger, what would happen to the signal received?
    Ans: The weak signals can be focus more. The signal received is more concentrated and stronger.

    Are my answers correct? Please give me some comments.
     
  2. jcsd
  3. Jun 8, 2004 #2

    BobG

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    All except for answer 4, which is worded a little weakly.

    The curvature of the dish determines the the focal point. The diameter of the dish determines how much energy is received (the signal is being broadcast to a much larger area than just the dish). So, more energy is received into the dish, resulting in more energy being focused into the antenna sitting at the focal point.

    Just about what you said.
     
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