February 7, 2012
Electric Fields Lab
In this lab we will study the equipotential lines in an electric field in order to study the structure of the electric lines of force. We will plot the position of electric field lines in a given electric field using both a manual method and a computer software program. There is an electric field in any region where there is a force on an electric charge at rest. It is convenient to represent an electric field by the lines of force. The direction of the lines is the direction of the force on a positive electric charge in the field. The electric field intensity at any point is the force that would be exerted on a positive test charge, +q, at that point. The electric field intensity is proportional to the number of electric lines of force per unit area. An equipotential line is a set of points that all have the same potential. Since there is no change in potential, no work is required to move a charge on an equipotential line; therefore there is no component of electric force along an equipotential line. Electric lines of force are always perpendicular to equipotential lines.
Applying Coulomb’s Law we have:
Fes=k (Q1Q2)/r2 (1)
The electric field that a test charge (q) experiences is defines as:
d=1/ (Q / Q)^(1/2) -1 (3)
A field pattern template with two circular terminals was attached to the field mapping board. A 9V battery and a voltmeter were then attached to the mapping board with leads. A third lead was then connected to the top of the mapping board. A U-shaped probe was attached...