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demonstrations:5_electricity_and_magnetism:5k_electromagnetic_induction:thompsons_jumping_rings:start
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demonstrations:5_electricity_and_magnetism:5k_electromagnetic_induction:thompsons_jumping_rings:start [2019/02/14 23:33] 127.0.0.1 external edit |
demonstrations:5_electricity_and_magnetism:5k_electromagnetic_induction:thompsons_jumping_rings:start [2020/03/11 15:47] (current) demoroom |
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| ====== Thompson's (jumping) Rings ====== | ====== Thompson's (jumping) Rings ====== | ||
| - | {{tag>Thompson Jumping Rings needs_review untagged unlocated}} | + | {{tag> electricity_and_magnetism solenoid ac lenz levitation located}} |
| <WRAP box right> | <WRAP box right> | ||
| Line 11: | Line 11: | ||
| ===== Description ===== | ===== Description ===== | ||
| - | This iron core solenoid is a great demonstration of Lenz's Law. By using AC straight from the wall, it demonstrates how induced current from a magnetic field depends on a change in magnetic flux, and the resulting Lorentz force from these currents causes the rings to levitate! Simply set the device to "float" mode, and place a ring around the core, and it will float. If the device is set to "jump," then the solenoid will receive a short pulse of electricity, and since that translates to an enormous change in flux, the ring jumps! Classes Used: Phys 102, 108 | + | An iron-core solenoid with two switches- a momentary switch and a toggle switch- is mounted inside a plexiglass enclosure and has a power cord to connect to mains power. The top has a post lined up with the axis of the solenoid so that conducting rings may be stably levitated over it. |
| - | + | ||
| - | + | ||
| - | + | ||
| - | There are several rings available, various aluminum rings, including one with a slit cut in it to demonstrate that a flowing current is required, a brass ring, and a light bulb connected to many coils that lights up when placed over the solenoid. For the ring with the slit, one can demonstrate that the floating is due to an inductive and not a resistive effect. Connecting alligator clips across the slit will do nothing, but inserting a aluminum sheet into the slit will restore some of the ring's jumping properties (of course there is still a finite air gap between the ring and the inserted sheet metal). | + | |
| ===== Purpose ===== | ===== Purpose ===== | ||
| + | This iron core solenoid is a great demonstration of Lenz's Law. By using AC straight from the wall, it demonstrates how induced current from a magnetic field depends on a change in magnetic flux, and the resulting Lorentz force from these currents causes the rings to levitate! | ||
| + | There are several rings available, various aluminum rings, including one with a slit cut in it to demonstrate that a flowing current is required, a brass ring, and a light bulb connected to many coils that lights up when placed over the solenoid. For the ring with the slit, one can demonstrate that the floating is due to an inductive and not a resistive effect. Connecting alligator clips across the slit will do nothing, but inserting a aluminum sheet into the slit will restore some of the ring's jumping properties (of course there is still a finite air gap between the ring and the inserted sheet metal). | ||
| ===== Apparatus ===== | ===== Apparatus ===== | ||
| + | * Jumping ring apparatus | ||
| + | * Aluminum ring | ||
| + | * Aluminum ring with slit | ||
| + | * Copper solenoid with lightbulb | ||
| ===== Setup ===== | ===== Setup ===== | ||
| + | Simply set the device to "float" mode, and place a ring around the core, and it will float. If the device is set to "jump," then the solenoid will receive a short pulse of electricity when the momentary switch is pressed, and since that translates to an enormous change in flux, the ring jumps a couple feet into the air. Be prepared to catch it! | ||
| + | When the device is in "float" mode((Using the "jump" mode while the solenoid is on the apparatus may damage the light bulb.)), the copper solenoid may be placed onto the apparatus. As it gets closer to the solenoid it'll light up, getting brighter and brighter and illustrating, in another way, that current is flowing. | ||
| ===== Notes ===== | ===== Notes ===== | ||
| Line 47: | Line 50: | ||
| </WRAP> | </WRAP> | ||
| <WRAP tablewidth 100%> | <WRAP tablewidth 100%> | ||
| - | | **Location** | ---- | | + | | **Location** | Q4 | |
| | **Maker** | Unknown | | | **Maker** | Unknown | | ||
| | **Current State** | Working | | | **Current State** | Working | | ||
demonstrations/5_electricity_and_magnetism/5k_electromagnetic_induction/thompsons_jumping_rings/start.1550187203.txt.gz · Last modified: 2019/02/14 23:33 by 127.0.0.1
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