Faraday's Law (MBL) Pre-lab Assignment

Your name: _____________________

Print this page, record your answers on it, and show it to your lab TF at the start of your lab session. In the lab you will use a computer to collect data when you drop a magnet through a coil, inducing an emf. Click the button below to run a simulation of a magnet passing through a loop. Graphs are drawn of the magnetic flux in the loop, and of the induced voltage in the loop, as a function of time. You will work with similar graphs in the lab. In the simulation the magnet moves at constant speed.

1. The first graph shows that the magnetic flux is maximum when the center of the magnet is at the center of the loop. What is the induced emf at this instant? Explain why the emf has this value at this instant.

2. In the simulation positive flux corresponds to field lines passing from left to right through the loop. Would either of the graphs change if the magnet was turned around and the south pole passed through the loop first? If so, explain any changes you would observe in the graphs.

For the last two questions the orientation of the magnet is the same as shown in the simulation, with the north pole passing through the coil first, but the velocity of the magnet is doubled.

3. Would the graph of magnetic flux change? If so, describe how. Particular features of the graph you should consider are the height of the peak, the time at which the graph peaks, and the width of the peak. Sketch the new magnetic flux graph, with the original graph from the simulation shown for comparison.

4. Would the graph of induced emf change? If so, describe how. Consider the same features as in the previous question. Sketch the new graph, with the original graph from the simulation shown for comparison.