Applied Science - Physics (3B)
Pre Lab 

   
OBJECTIVES:
  • Investigating electricity.
  • Comparing static and current electricity.

VOCABULARY:

  • current
  • electricity
  • electrons
  • static
MATERIALS:

Students see a demonstration of static electricity.

BACKGROUND:

There are 2 basic kinds of electricity: static electricity and current electricity. Static electricity is uncontrolled electrons passing from one body to another in sudden, momentary movements. Examples include clothes from the dryer that stick together; or getting a shock after walking on a carpet and then touching something. Static electricity is usually a nuisance and a hazard that can cause fires.

Current electricity is when the electrons are controlled by moving along a path together. The path is usually a conductor of electricity. A copper wire can move electricity from a power plant to a house.

PROCEDURE:

  1. Static electricity can be illustrated by showing students the plasma ball. Plasma is stripped electrons, which is basically what static electricity is. In many plasma balls, the plasma gives off a light different than most static electricity we are used to. Demonstrate the different ways you can control some of the electrons by putting your hand to the ball. This demonstration looks better in a dark room. Put a small fluorescent tube to the Plasma Ball. Notice that the electrons will light the tube. The electrons go through the tube and excite the gas to give a glow.
      
    The electricity is always looking for the "ground." So it uses your body to conduct the electricity. However, it is not enough electricity to cause any harm.
      
  2. Current electricity is controlled; the electrons all move in one direction. Wire can transmit electricity so it becomes a very useful energy source. When its movement along a wire is controlled, it is current electricity. Remember, electricity is a flow of electrons in one direction.
      
  3. On the board, have students make a list of their experience with electricity. Put it in 2 columns - CONTROLLED (CURRENT) and UNCONTROLLED (STATIC), as illustrated below. Students are sure to bring up lightning which is a visible discharge of electricity. This will be explained in the post lab.

   

CONTROLLED

UNCONTROLLED

electric circuit
electric oven
electric can opener

 

when clothes get stuck
when socks stick to clothes
when confetti gets stuck on items

 

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