Formal Lab Report
By David Deng
The Electromagnetic Force: An Equation
This lab is to measure the determinant factors of the size of electromagnetic force that affect with electric and magnetic fields. The electromagnetic force is carried by the photon and is responsible for atomic structure, chemical reactions, the attractive and repulsive forces associated with electrical charge and magnetism, and all other electromagnetic phenomena. According to Coulomb’s Law, we know electric charges get Coulomb force in the electric field while current receives another applied force, which is Ampere force when it is in a magnetic field. Overall, electromagnetic force is the force that electric charges and current are acted in the electromagnetic field. Electromagnetic force is one of the four fundamental forces in nature. Currently, people can produce strong electromagnetic fields as well as strong electric current due to advanced engineering technologies. Besides, we can obtain a great deal of electromagnetic forces (electrostatic forces) from it. Additionally, it seems that electromotor is driven by magnetic force and electromagnetic force has some further applications such as electrostatic instruments and dust catcher. Overall, this study plays an important role in both our studies in physics and the development of electromagnetism.
In this typical experiment, we used controlling variables method to determine the relationships among how current (I), length of wire (L), and strength of magnetic field (B) affect the size of the electromagnetic force that was exerted on the wire. More precisely, we did three separate experiments to obtain each result by using the same method. Diagram 1 Schematic diagram of the experiment
In terms of the relationship between current and the size of the electromagnetic force, we used a digital ammeter to display these current values while we increased the current by using a regulated power supply to provide different required amounts of current. In the meantime, we kept the other two variables, which are magnetic field strength and the length of wire constant and wrote down the results. Likewise, we switched to another variable B, magnetic field strength and used the same way to measure the relationship between B and FB, the size of the electromagnetic force. The equipment we used to control the variable B is a magnet that is assembled with 6 small removable horseshoe magnets. We increased the strength values gradually and recorded the changes in the size of the force. The strength of this field was measured using a hand held magnetic field probe and meter. For the third variable L, the length of wire, we used several small current loops, with plugs attached, allowing them to be suspended in the magnetic field, perpendicular to that field. Similarly, we added the length and kept the current and magnetic field strength unchanged. Apparent mass increased was measured using the 0.01gram balance. According to Newton's 3rd Law, when the magnet assembly pushes the current loop up with a force FB, the current loop also pushes the magnets down with the same amount of force. You can see results and observations below. Results
(a) Magnetic Force on a Wire as a Function of Current in the Wire. Current (I) in A| Apparent Mass Increase in g| Magnetic Force (FB) in N| | 1| 0.22| 0.00216| Length of Wire =4.2cm =---| 2| 0.46| 0.00451| =0.042m| 3| 0.68| 0.00667| Magnetic Field = 55.3mTesla|
4| 0.91| 0.00893| =0.0553Tesla|
5| 1.14| 0.01117| |
6| 1.37| 0.01344| |
Current (I) in A| Apparent Mass Increase in g| Magnetic Force (FB) in N| | 1| 0.22| 0.00216| Length of Wire =4.2cm =---| 2| 0.46| 0.00451| =0.042m| 3| 0.68| 0.00667| Magnetic...