PIRA 5K10.50 - 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
Experiment 1a setup
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
Experiment 1b setup
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
Experiment 2 setup
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
Experiment 3 setup
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.
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