The report contains information about a descriptive lab conducted to test and observe Coulomb’s law. Thus, the purpose of the laboratory experiment was to observe the electrostatic force between two charged spheres. In particular, its dependence on the distance between objects and their charge. Thus, when q1 and q2 are separated by a distance r, one can find the electrical force between them. The equation for Coulomb’s law is shown in the image below, where k is a Coulomb’s constant.
Materials and Procedures
The devices required for the experiment are the Coulomb balance apparatus and high voltage power source (0-6 kV), two conductive spheres, plastic rods, and a ruler. Two identical conductive spheres are also required, one of which is balanced and suspended on a thin torsion wire. The second sphere is located on a slide assembly so that its distance from the suspended sphere can be adjusted. The spheres must be held in place with plastic rods for electrical insulation. The ruler measures the distance between the centers of the two spheres.
The first procedure is to measure the force between two charged spheres. The experiment consists of several steps (Coulomb’s Law Experiment):
- Charging the spheres.
- Moving the stable sphere one centimeter closer to the suspended one each time.
- Recording the distance and the torsion angle representing the force between two spheres.
In the second part of the experiment, to measure the dependence of the electricity depending on the charge, it is necessary to change the number of kilovolts while the distance is constant (6, 4, 3, and 2 kilovolts).
Analysis and Conclusion
To conduct the analysis, it is necessary to record the obtained data in two tables and then build dependency graphs on them. Based on these graphs, conclusions can be drawn about the proportional dependence of the electric force on the distance and charge of the spheres. During the experiment, it was revealed that the electric force is directly proportional to the product of two charges and inversely proportional to the square of the distance between them.
“Coulomb’s Law.” Toppr, Web.
“Coulomb’s Law Experiment.” YouTube, uploaded by pascoscientific, 2015, Web.