Faraday's Magic

Equipment

• bar magnet
• coil of wire
• galvanometer
• compass

Please handle the coils and galvanometers with care so that they are not damaged!

Moving a magnet near a coil

1. Use the compass to check that the north end of the magnet is correctly labeled :)

2. Connect a coil of wire to a galvanometer. The lead that comes from the inside of the coil should be connected to the (-) terminal of the galvanometer. The lead that comes from the outside of the coil should be connected to the (+) terminal of the galvanometer.

3. Hold the coil so it is vertical and the lead connected to the (+) terminal is on top of the coil.

1. Hold the magnet so its axis is along the axis of the coil, with the North end toward the coil.
   1. Prediction: As you move the magnet toward the coil:
      • What is the direction of ?___________
      • What is the direction of the curly electric field at the location of the coil?___________
      • Should the galvanometer give a positive or negative reading? ____________
   2. Move the North end of the magnet toward the coil.
   3. Record the galvanometer reading. Was your prediction correct?_________________
   4. Prediction: As you move the magnet away from the coil:
      1. What is the direction of ?_________________
      2. What is the direction of the curly electric field at the location of the coil?____________
      3. Should the galvanometer give a positive or negative reading?_______________
   5. Move the North end of the magnet away from the coil.
   6. Record the galvanometer reading. Was your prediction correct?__________________

4. Repeat with the south pole of the magnet closest to the coil.

Questions

1. When was the galvanometer reading positive? When was it negative?

Draw a diagram showing the directions of and the curly electric field in each case. (There should be 4 cases).

Put your diagrams on the wall whiteboard.

2. How could you make the direction of the electric field alternate?____________