What Is Electricity

Oldenburg, Albert               Lindblom Tech High School
                                471-8700
                           

Objectives:

To develop an understanding of the fundamentals of static electricity, 
namely that of materials, conditions, and charge. To learn how to 
detect a charge by the use of electroscopes. To learn how to determine 
the force between charges. 

Materials  

Demonstration Van de Graaf generator, Jacobs ladder, thread, aluminum 
foil, long plastic tubes (golf club protectors), cat or rabbits fur, 
ebonite rods, glass rods, ring stands, silk pieces, scissors. 

Strategy:

This lesson is usually scheduled as the first in a series at the 
beginning of the second semester. In fact, the concepts given today are 
usually spread over three to five class periods. The equipment is set 
up before class time. Then some time is spent checking to see if it is 
working properly. One must work very carefully with the Jacob's ladder 
coil because its output can be deadly, therefore extreme caution must 
be practiced. It has also been suggested that a clear plastic shield 
should enclose the apparatus for safety purposes. The lesson starts 
with the question, "What is electricity?". The student's response gives 
one six or seven ideas which are written on the blackboard and then are 
emphasized with the demonstrations. After these are completed the 
students are divided into groups due to lack of equipment and are pre-
instructed how to rotate from station to station doing all three parts 
of the lesson which consisted of detection of charge, making an 
electroscope, and determining the amount of force produced by the 
charge on an object. At least three trials are to be used on the force 
part and or using different materials to familiarize the student with 
the workings of Coulomb's Law. After the groups have been finished, the 
class as a whole will discuss the concepts and develop a consensus for 
their lab reports to be turned in a few days later.