Lab10 100 Magnetics OL

Physics 100 Lab 10 Magnetism & Electromagnetism Each group should complete and submit a copy of the lab so it is important that all group members agree with the answers to the questions. Group Member (print) _________________________________________________ Group Member (print) _________________________________________________ Group Member (print) _________________________________________________ WARNING – Keep all Magnets and Coils away from Computers For this lab you will need the following equipment: 750 interface bar magnet magnetic field sensor zero gauss chamber 3 D cell batteries meter stick ( without metal ends ) 2 similar light bulbs with holders compass jumper wire with alligator clips tape Investigation 1: Magnetic Field of a Permanent Bar Magnet Procedure 1. Connect the magnetic field sensor to the 750 interface and under ‘ Hardware Setup ’ in Capstone . Double click on the ‘ Digits ’ display in Capstone . 2. Click on ‘ <Select Measurement> ’ and select the ‘ X1 ’ range in the ‘ Digits ’ display window and on the sensor . The range selection must match for both the hardware ( sensor ) and the software ( Capstone ) . 3. Slide the field selector switch on the top of the magnetic field sensor to the AXIAL position. 4. Click on ‘ Record ’ in Capstone to begin measuring magnetic field. 5. While recording, click on the units ‘ (T) ’ in the ‘ Digits ’ display window and select ‘ (gauss) ’. 6. With the sensor inserted into the gauss chamber, zero the sensor by pressing the tare button. 7. Place the meter stick on the table, away from the computer. 8. Place the magnetic field sensor so the end of the sensor rod is even with the 0.0 cm end of the meter stick. 9. Keeping the magnet away from the computer, place the magnet next to the 0.5 cm mark on the meter stick with the north pole of the magnet facing the sensor. 10. Record the value of the magnetic field at the 0.5 cm mark in the table below. 1

11. Move the magnet another 0.5 cm away from the sensor and record the new value, repeating this process to complete the table below. 12. Open Capstone and click on ‘ Manual Entry ’ from the 6 data analysis options in the center of the window. Enter your data to graph B field ( y axis ) vs location ( x axis ). Title your graph and label the x and y units by clicking on ‘ units ’ in the table under each x and y column. 13. Use the curve fit tool to find the best fit for your data. The closer r is to one or the closer rmse is to zero the better the fit. Print and attach your graph to your lab. Location x [cm] B [Gauss] 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Question 1-1: Does the magnetic field strength increase or decrease as the distance from the magnet is increased? Question 1-2: Is the relationship between magnetic field strength and distance linear? Question 1-3: Based on the results of the curve fit, what do you conclude is the relationship between the magnetic field strength and the distance from the magnet? 2

5. Reverse the orientation of the battery by disconnecting the wires from the battery and then reconnecting them at opposite ends of the battery. Question 2-2: What needle deflection do you observe when you close the loop after you reverse the battery orientation? What do you observe when you break the loop? Closed Loop: Clockwise Counter-clockwise ( Circle one ) Open Loop: Clockwise Counter-clockwise ( Circle one ) How does this compare with your results in Question 2-1 above? Question 2-3: What do you think might be happening in the wires to make the compass deflection change direction when the battery orientation is reversed? Explain your reasoning. Question 2-4: If something is moving in the wires, does the direction of movement and the amount of movement appear to be the same in every wire of the circuit at one time? What is the evidence ( how can you test it )? 4

Question 2-5: What do you think the battery does in this circuit? What is the evidence? Question 2-6: Can a compass be used to identify the direction of movement within a wire? Explain carefully. 5