Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Homework on transmitter

  1. Jan 21, 2005 #1
    We were asked to make an educated guess of how the following would react - as transmitters, reflector, partial reflect, or absorder when a plate of the following was placed at a 45 degree angle as shown in the attachment

    The transmitter transmits microwves in a straight line and the following are placed along the solid line that is drawn between. The Detectors will detect whether the microwaves are reflected or absorbed

    The following were placed al9ong the solid line - Nothing, Wood frame wrapped with Aluminium foil, Solid Aluminium plate, Plexiglass, Solid Copper plate, and a Wire Mesh

    Following are what i mthink may happen.

    When nothing is placed then detector 1 will detect all of the microwaves that were transmitted because nothing is obsturcting the waves. Nothing will be detected at detector 2

    When aluminium foil wrapped on wood frame is placed it will reflect all but since it is thin it will transmit some and the wood block with abosrb whatever is transmitted.
    When a solid aluminium plate is placed it will reflect all of the light?

    When plexiglass is placed it will abosrob all teh light??

    When a solid copper plate is placed it iwll reflect all

    When a mire mesh is placed it iwll reflect all of it ??

    Attached Files:

  2. jcsd
  3. Jan 22, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    In fact, it will transmit most of the waves if it is thin compared to the wavelength. Typical aluminum foil is less than 1mm thick, and the microwave wavelength is about 12 cm. So, most of the energy will be transmitted through the foil and absorbed by the wood. A little bit will be reflected.

    Depending on the thickness, but I think this is mostly right. Thin plexiglass will transmit some too.

    I think you've got it all.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook