Q2. [2.5 pts] Draw a top-down 2D diagram of your setup in part E of the lab manual (imagine looking from above). This diagram should include:a. The cardinal directions (N,S,E,W)b. The direction of current in the wires ( x for into, and O for out of the page)c. The direction of the compass needled. A vector representing the Earth's magnetic fielde. A vector representing the wire's magnetic field at the compassf. The vector representing the total magnetic field at the compassg. Labels for measured distances (d), angles(0), and currents (I)
E2. Test your setup: turn the power supply on and verify D7. Do the field lines outside of the magnet connect to the field lines inside the magnet? Do that you get a current of about 2.0 A. (This may not your field lines agree with what you know about magnetic domains and the behavior of correspond to 2.5 V, which is ok) Do not leave the supply magnetic field lines? Check with your TA to make sure you're on the right track. on for more than 10 seconds to avoid overheating. Note the current and the number of wires in your setup. O = North D8. Hit the nail several times with a hammer. (Try to hit each region of the nail) Does it still have the same effect on the compass? Does adding energy in the form of hammer strikes E3. Using a compass observe and record the direction of the make the domains more or less organized? magnetic field at several points near the wire when the current is zero. Does this agree with the measurements you Now repeat the procedure of D1-D5 with the glass tube of iron filings. Shake it up and hold it made in experiment C? NorIN horizontally with the iron filings spread uniformly along the tube. E4. Place the compass somewhere on the box's platform, D9. Do the filings initially have any effect on the compass? Do the filings move when near the BEFORE you turn on the power supply, predict what you magnet? What happens when you rub the filings with the magnet? expect to see when the current is not zero. Use the figure on the right to help, and consider D10.Can the iron filings be magnetized? How can you tell? Is there any way to tell what the the right hand rule for generating magnetic fields from a straight current. Which way does magnetic field is like inside the glass tube? the thumb point? Which way do the fingers point? D11. Thinking back to the hammer, what effect do you expect shaking the tube will have on E5. Now turn on the power supply, and which way the compass points with the current on. the iron filings? Shake the tube and bring it near the magnet. What happens? What effect What does this have to do with the magnetic field where the compass is? Start with the does adding energy to the filings by shaking them have on its magnetic domains? compass north of the wires. Now move the compass to directly north of the wires. Which way does the field point there? Also note the field direction with the compass E, S, and W PLEASE discard all used nails into the appropriate box on the front table. of the wires. E6. Is the direction and shape of the magnetic field you observe consistent with predictions E: MEASURING EARTH'S MAGNETIC made with the right hand rule? FIELD The goal of this section of the lab is to measure the Earth's E7. Change the direction of the current through the straight wire. Is the magnetic field magnetic field. Since the B-field produced by the Earth is a consistent with the right hand rule? vector, it has a magnitude and a direction, You have already E8. At what position relative to the wires is the magnetic field of the current perpendicular to measured the direction of the Earth's B-field, so all that is left the Earth's magnetic field (Choose N,S( E, W)? Set the compass at this position. Are there to measure is its magnitude. By introducing another magnetic any other places that you could place the compass so that the magnetic field produced by field (produced by the coil of wire attached to the wooden box) the current is perpendicular to Earth's field? Check with your TA to make sure you placed and using the compass, you will be able to measure the total magnetic field ( Earth and wire the compass at the right spot. West IE Nors Field compass fields combined), and use that information to infer the magnitude of the Earth's field alone. relative E9. Record the angle the needle makes on the compass. Turn the power supply back on, letting Practical considerations restrict the current to about 2.0 A. To overcome this we have multiple the needle settle, and record the angle it makes with the current on. Does it point in the wires running parallel to each other, each carrying about 2.0 A. This setup also has a platform direction the right hand rule would suggest for it to? Why or why not? Adjust the current where you can place a sheet of paper and a compass. You can mark the angle of the compass needle on the paper. until you get to a 45 degree angle. L 3. 10 current to get 450 + 50 E1. Before you connect the loops of wire to the power supply, set the current limit of the E10. Calculate the magnitude and direction of the magnetic field as produced from the supply to its maximum value, and set the voltage to 2.5 V. (This is just to make sure there current alone at the compass' position. Remember to record the uncertainties for each is not too much current in the wires when you turn the supply on.) Then switch the supply measurement you needed to make for this calculation. Why is the uncertainty in the to read current, and turn the power supply off. Cut a sheet of paper to fit around the wire distance measurement larger than 1 mm? and rest on the platform to record the direction of the magnetic field. Set up the circuit so 11 The compass points in the direction of the local magnetic field, which can be the vector that the "conventional" current is flowing upwards. sum of magnetic fields produced by different sources. Draw the vector diagram of the two magnetic fields and the resultant field. (Hint: you know the size and direction of the field from the wires, and the angles of the Earth's field and the resultant field.) What is the magnitude of the Earth's field as calculated from your measurements
