How long will a rotating magnet generate electricity?

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Discussion Overview

The discussion revolves around the generation of electricity by rotating a permanent magnet, specifically focusing on the duration of electricity generation and the nature of magnetic energy. Participants explore concepts related to generators, the characteristics of magnets, and the relationship between mechanical energy and electrical output.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant inquires whether a rotating metallic cylinder that is a permanent magnet can generate electricity and questions how long this generation lasts.
  • Another participant suggests that the magnet needs to be polarized and describes the setup as resembling a generator, stating it will generate electricity until it stops rotating or wears out.
  • There is a question about the feasibility of using a cylinder or tube as a magnet and whether it can be made magnetic, along with concerns about the longevity of electricity generation.
  • A participant clarifies that a magnet is not a source or store of energy, emphasizing that the energy produced comes from the external source that spins the magnet.
  • Some participants challenge the notion that magnets can store energy, discussing the conservation of energy and comparing it to a mass bouncing on a spring.
  • One participant provides a link to introductory reading on how magnet-based generators work, suggesting it may help clarify the concepts involved.

Areas of Agreement / Disagreement

Participants express differing views on the nature of magnets as energy sources and the mechanics of electricity generation. There is no consensus on the specific characteristics required for the cylinder to function as a magnet or the duration of electricity generation.

Contextual Notes

Participants do not provide specific details about the assignment mentioned, which may affect the applicability of their responses. The discussion includes assumptions about the nature of magnets and energy that remain unresolved.

Who May Find This Useful

This discussion may be useful for students or individuals interested in understanding the principles of magnetism, electricity generation, and the mechanics of generators.

physior
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hello!

If I rotate a metallic cylinder that is a permanent magnet, it will generate electricity in a wire next to it?

for how long it will generate electricity? forever? or it phases out as the magnetic energy transforms to electricity? how long it will last approximately?

thanks
 
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The magnet can't just be a cylinder, it needs to be polarized. Individual magnets arranged in a circle would do it. You are roughly trying to describe a generator.

And it will continue to generate electricity until you stop rotating it or its parts wear out. In the real world, that takes several decades.
 
thanks
why it can't be a cylinder?
I can only use a cylinder or a tube! isn't there a way to be it magnetic?
also, can I make it magnetic? will it still take decades to phase out? it will give electricity for decades? what amount of electricity?
 
for how long it will generate electricity? forever? or it phases out as the magnetic energy transforms to electricity?

A magnet is not a source or store of energy.

Ultimately the energy produced comes from whatever is spinning the magnet. The energy does not come from the magnet so it doesn't "wear out" the magnet.
 
how is not magnet a store of energy? it has the potential to produce work by moving a magnetic item!
 
physior said:
thanks
why it can't be a cylinder?
I can only use a cylinder or a tube! isn't there a way to be it magnetic?
also, can I make it magnetic? will it still take decades to phase out? it will give electricity for decades? what amount of electricity?
So this is for an assignment? Without knowing the details of the assignment, I'd just be guessing about what you should do.
 
physior said:
how is not magnet a store of energy? it has the potential to produce work by moving a magnetic item!
That work is symmetrical/conserved. And more to the point, the magnetic field isn't consumed when doing the work. Picture it like a mass bouncing on a spring.
 
physior said:
hello!

If I rotate a metallic cylinder that is a permanent magnet, it will generate electricity in a wire next to it?

for how long it will generate electricity? forever? or it phases out as the magnetic energy transforms to electricity? how long it will last approximately?

thanks

Here is some introductory reading that should help you understand how magnet-based generators work:

http://en.wikipedia.org/wiki/Electric_generator

:-)
 

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