代写PHY 134.L69 Magnetic Force Lab Report帮做R程序

PHY 134.L69

Magnetic Force Lab Report

Introduction

In this lab, we explored the fundamental principles of magnetic fields. Our objectives are to measure magnetic field strength and direction, derive the field of a wire, verify the shape of the magnetic field around a wire, and verify that the magnitude of the field falls off as 1/r. The main concepts that falls within this lab are the Ampere's law and the right-hand rule. Ampere's law is a fundamental equation in electromagnetism that relates the magnetic field along a closed loop to the electric current passing  through the loop. It is mathematically expressed as: ∫B·dL=μ0Ienc, where ∫B·dL represents the line integral of the magnetic field B along a closed loop, μ0 is the permeability of free space, and Ienc is the total electric current enclosed by the loop.

Procedure

1. Open up the computer and get the iOLab and stuff set up.

2. Calibrate the sensor of the iOLab and verify the accuracy of the calibration.

3. Set the iOLab in the center of a stack of paper.

4. Mark the magnetometer on the paper with a pen and then draw a straight line that's parallel to the short side of the paper.

5. Click on the magnetometer in the software and unclick Bx and Bz.

6. Start collecting data.

7. Rotate the paper with the iOLad until the blue line has aligned with the 0 line.

8. Stop collecting data.

9. Take some tape and tape down the paper.

10. Tuck the 12ft wire under the paper and align the wire with the drawn line.

11. Tape down the wire.

12. Assemble three D batteries into the battery cage.

13. Connect the positive end of the wire to the left postive power rail on the breadboard and the negative end to the right negative power rail.

14. Get one 0.5Ω resistor and connect one end to the left positive power rail and the other end to an arbitrary hole in the center region.

15. Get another 0.5Ω resistor and connect one end to the right negative power rail and the other end to an arbitrary hole in the center region (not in the same row as the previous one).

16. Connect the ground on the iOLab to the left postive power rail on the breadboard with a wire.

17. Connect the A7 on the iOLab to the left resistor on the breadboard with another wire.

18. Plug one end of the 12ft wire into the same row as one of the resistors and the other end into the same row as the other resistor to close the circuit.

21. Record the data for a few seconds.

22. Disconnect the current and the iOLab.

23. Put the iOLab on the paper facing down and align the shorter edge of the iOLab so that it's parallel to the drawn line.

24. Start collecting data.

25. Roll the iOLab back and forth of the paper for a few times.

26. Stop collecting data.

Results

In this figure, the voltage V across the 0.5Ω resistor is 0.8615V, by applying Ohm's Law, the current across the resistor is 0.8615/0.5=1.723A. The darker measurement measured the voltage while the iOLab is rolling.

For these two figures above, the left one has a peak around x-axis -42μT to -43μT and y-axis around 0. 06m. The right one has a peak around x-axis 42μT to 43μT and y-axis around 0.06m (I don't know why but I can't find any highlighting tool). They reflect thus do circle the wire as we expect.

This figure shows us that ∆By is about -5-(-43)=38μT and ∆Bz is about 60-23=37μT. So ∆Bz/∆By= 38/37=1.03. Which is approximately 1.

Conclusion

In this lab, we investigated the behavior. of magnetic fields generated by current-carrying conductors. By applying Ampere's Law, we were able to understand the magnetic field patterns for straight wires. The experimental results aligned well with the expected results, confirming the relationship between current, distance, and magnetic field strength.