Induced Currents and Forces: Electromagnetic Experiment
Make sure to add a note of which experiment you want when requesting!! Different experiments require different set-ups.
Concepts Conveyed:
- Behavior of a current-carrying conductor in a magnetic field (Experiment 1)
- Induced eddy currents (Experiment 2)
- Diamagnetism and paramagnetism (Experiment 3)
Instructions
- Note: For every experiment, make sure that the bars and the entire set up are aligned properly because this can affect the position of the rods, copper wire, and pendulums.
Experiment 1a: Induced Force on Current in Wire
- Use the adjustable silver screw at the center of the magnet attachment to attach the magnet-screw system to the vertical bar of the stand. The copper wire should be suspended in between the magnets by screwing its bar onto the top of the upper bar of the stand.
- Plug in the blue and red wires from the 20V/5A power supply into the copper wires.
- Slowly increase the current (in A) through the wire, not exceeding 6A. The conductor swing should displace either to the right or left. As the current increases, the swing should displace a greater distance.
Experiment 1b: Lorentz Force
- Attach the magnet-screw system to the horizontal bottom bar. The copper wire is suspended in between the magnets by screwing its bar onto the bottom of the upper bar of the stand (use the first hole on the top silver bar to screw the bar).
- This time, increasing the current in the wire does not displace the conductor swing in any direction. This is because the Lorenz force does not act in the direction of the magnetic field or current flow.
Experiment 2: Eddy Current Pendulum
- Remove the two magnets and adjust the magnet-screw system to be closer together.
- Hang the solid pendulum and slotted pendulum onto any two slots on the pendulum axle mount. The magnet-screw system is attached to the horizontal bar, as in Experiment 1b.
- Displace the pendulums at the same angle and release.
- The solid pendulum should come to a full stop before the slotted pendulum does. This is because the slotted pendulum does not allow for the buildup of eddy currents.
Experiment 3: Magnetic Properties of Materials
- The setup of the magnet system is identical to experiment 2. Instead of using the pendulums, we will instead hang the glass or aluminum rod. You can use any slot from the black axle mount, just make sure to adjust the magnet screw system accordingly.
- Suspending the glass rod between the magnets will cause it to rotate one way and then the other.
- Suspending the aluminum rod will cause it to rotate completely before stopping parallel to the horizontal bar (in the direction of the magnetic field).
- Explanation: The rods align themselves in the magnetic field. Due to the different materials, their relative permeabilities are different. These differing permeabilities cause differing flux densities in each rod.
Demo Staff:
- Ensure that the setup is aligned properly. To do this, setup experiment 3 and ensure the center of mass of the rods are aligned with the magnet-screw system.
Last updated on April 10, 2024