Electricity

Julian Levey                   Teachers Acad. for Math and Science
                               10 W. 35th St
                               Chicago IL 60616
                               (312)808-0100

Objectives:

This lesson is appropriate for all grades from 5th through high school.  The
main objective is to teach elementary electricity principles with the use of
materials which are easily available.

Materials Needed:

1.5 volt batteries (D cells)
3 volt bulbs and sockets
hook-up wire (thin)
single pole knife switches
3 volt buzzers
3 volt motors
battery holders for 2 batteries
These items are obtainable at American Science Center or Radio Shack.

A typical kit for three students working as a group would consist of 
2 batteries, 4 bulbs, 4 sockets, 12 pieces of wire (about 8 inches long and 
stripped at each end), 2 knife switches, 1 buzzer and 1 motor. 

Strategy:

Describe and illustrate the flow of electrical current from the battery,
through the wires and through a bulb.  Have the students construct a simple
circuit using a single bulb:


This can be followed by the introduction of a switch into the circuit to show how the light can be turned on and off.

The next step would be an explanation of parallel circuits where the electrical surrent from the battery flows with equal voltage into two or more bulbs.

After the students have hooked up this circuit, they can then hook up a series circuit where the electrical current from the battery flows first through one bulb and then through the other. 

Students can then be directed to loosen various bulbs in their sockets to show 
that a bulb will remain lit in a parallel circuit even though another bulb may 
be out.  This can be compared to the series circuit where the loosening of one 
bulb in the circuit will cause any other bulb in the circuit to go out also. 

A further step would be the hook up of a parallel circuit using different
components such as bulbs, buzzers and motors.

Performance Assessment:                                               
 
Grading the student on his or her performance should be based on two factors:
1. The ability to construct the circuits accurately and have them work properly.
2. The ability to explain the circuits by tracing the flow of current from the
battery through the various elements of the circuit.
Each of these factors should be weighted at approximately 50% of the grade.

Return to Physics Index