Delmar's Electricity, Unit 3 Electricity.txt

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Delmar's Electricity, Unit 3 Electricity.txt
2013-02-13 19:32:00
static electricity

Question unit 3
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    • author "me"
    • fileName "Delmar's Electricity, Unit 3 Electricity"
    • tags "Static Electricity lightning"
    • description ""
    • Why is static electricity considered to be a charge and not a current
    • Static electricity refers to electrons that are sitting still and not moving.
  1. If electrons are removed from an object, is the object positively or negatively charged:
    Removing electrons from an object will render a positive charge.
  2. Why do static charges accumulate on insulator materials only?
    Insulators are the only materials that can hold the electrons stationary and keep them from flowing to a different location.
  3. What is an electroscope?
    An early electric instrument that can be used to determine the polarity of the electrostatic charge o an object.
  4. An electroscope has been charged with a negative charge. An object with an unknown charge is brought close to the electroscope. The leaves of the electroscope come closer together. Does the object have a positive or a negative charge?
  5. Can one thundercloud contain both positive and negative charge?
  6. A thundercloud has a negative charge, and an object on the ground as a positive charge. Will the lightning discharge be from the cloud to the ground or from the ground to the cloud?
    The lightning discharge travels from cloud to ground.
  7. Name two devices used for lightning protection.
    Lightning rods and lightning arrestors.
  8. What type of material is used to coat the aluminum drum of copy machine?
    Slenium, a semiconductor material that changes its conductivity with a change of light intensity.
  9. What special property does this material have that makes it useful in a copy machine
    When selenium is in the presence of light, it has a very high conductivity. When it is in darkness, t has a very low conductivity.