SP212 Lab: Eightà Faraday’s Law and Inductance
Version: March 20, 2014
1. Preliminaries Examine your 3200-­‐turn coil, and note the direction in which the coil is wound. (It is marked on the coil.) Place your coil on the table with the label showing the number of turns facing up. Connect the positive voltage clip to the bottom terminal of the coil, and the negative voltage clip to the coil’s top terminal. Now, for this configuration, predict the sign of the voltage that will be induced if you: Move the North end of your bar magnet toward the coil. Move the North end of your magnet away from the coil. Move the South end of your bar magnet toward the coil. Move the South end of your magnet away from the coil. Follow the three steps to set Logger Pro up to take data with the voltage sensor: Experiment -­‐> Set Up Sensors, Experiment -­‐> Data Collection -­‐> length = 4 s, Experiment -­‐> Data Collection -­‐> Sampling Rate = 200 samples/sec. Now, take data to test the four predictions you just made. How did you do? 2. Two linked coils
Place the two 3200-­‐turn coils side-­‐by-­‐side on the table, oriented in the same direction. Link the coils, in the magnetic sense, with the soft iron yoke. Connect the digital function generator (DFG) to the coil on the left; this will be the primary coil. Use the black and red terminals on your DFG. The voltage sensors measure the voltages across the primary and secondary coils. Since the primary is the “cause,” and the secondary is the “effect,” it is easy to compare if we all agree to place the graph for the primary below that for the secondary on the page in Logger Pro. Page 1 of 2 SP212 Lab: Eightà Faraday’s Law and Inductance
Version: March 20, 2014
Set the DFG as follows: Sine Wave, Frequency = 2 Hz, Amplitude = 5 V. Adjust the Primary voltage, take 5 sec worth of data. Discuss your observations. 3. Measuring Self-­‐Inductance Measure the radius of the 200-­‐turn coil and predict the inductance of the coil. Measure the inductance with the Mastech. Do they agree with each other and with your calculation? Page 2 of 2