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Homework Help: 2 questions in Electric and magnetic fields in space.

  1. May 9, 2005 #1
    Hey all I was just wondering if anyone knows how to figure out these two questions.

    1) The difference in potential between the cathode and the anode of a spark plug is 1.0x10^4V. What energy does an electron give up as it passes between the electrodes?

    This one I am really pretty clueless.

    2) Television channel 6 broadcasts on a frequency of 85MHz. What is the wavelength of the electromagnetic wave broadcast on channel 6? What is the length of an antenna that will detect channel 6 most easily?

    I read somewhere that to figure out radio wave length you take the megahertz and divide it into 300. Which works out to 3.5. I am not sure if this is the correct way to do it seems sort of simple.

    If anyone could give any help would be appreciated also any sites where I can better learn the material being used would be great. Thanks.
  2. jcsd
  3. May 9, 2005 #2
    1) Use the relationship between voltage and energy, its really simple.

    2) Speed of wave = Frequency * Wavelength

    Speed of wave = c = 3 x 10e8
    Frequency = 85MHz = 8.5 x 10e7 Hz
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