PreLab 1

1. Go to the website: phet.colorado.edu Click "Play with sims". Navigate to the "Physics" ? "Electricity, Magnets, & Circuits" section of the menu on the left side of the screen. Find the simulator "Faraday's Electromagnetic Lab". Run the simulator and play with it to familiarize yourself with its features. 2. In the "Pickup Coil" tab, the simulator has a magnet and a coil, the same equipment you will have in this experiment. Find as many ways as you can to make the light bulb light up. List them in your lab journal. There are at least 8 ways to make the bulb light! 3. For each way that you found to make the bulb light up, use Faraday's law to explain why current flows in the bulb.

Pre Lab 2

1. Derive an equation that relates the velocity of the magnet when it reaches the coil to the initial height of the magnet. (a) What variable are you trying to solve for in this problem and what variables are known? (b) Describe in physics terms what happens when the magnet is dropped. Is the magnet moving initially, just after it is released? What causes the magnet to move? Does the speed of the magnet increase, decrease or stay the same? Is the acceleration of the magnet constant? Is energy conserved? (c) Select a physics principle (kinematics, forces, conservation of energy, conservation of momentum, conservation of angular momentum, wave properties, optics, electric forces, circuits, magnetic forces) to use for this problem. (d) Write down the general equation for the physics principle that you selected.

(e) Translate your equation to variables appropriate to this problem. This should give you a fairly simple equation that involves the velocity when the magnet reaches the coil and the initial height of the magnet. (f) Solve your equation for the velocity of the magnet when it reaches the coil in terms of the initial height of the magnet and any other variables that are necessary. (g) Check that you equation makes sense. Are the units correct? If the initial height is increased, what happens to the velocity when the magnet reaches the coil? 2. Write down the general equation for Faraday's law. If the velocity of the magnet when it passes through the coil increases, does the time ?t increase, decrease or stay the same? Will the induced voltage be larger, smaller or the same if the magnet is moving faster? 3. Sketch a predicted graph of induced voltage vs. velocity of the magnet.

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