Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is power?

  1. Oct 10, 2004 #1
    I'm having difficulties understanding the concept of power and how you generate it in a circuit. Mainly I'm uncertain about how electrical energy can be used to produce power and what are the conditions for producing it (are resistors required?) Would someone be so kinda as to give me an anaolgy or an explanation in layman terms?
     
  2. jcsd
  3. Oct 11, 2004 #2

    Cliff_J

    User Avatar
    Science Advisor

    Ok, how about a physical analogy? Lets say you have a large fan like a ceiling fan. You can turn it by hand and make it spin, therefore you are performing work on it. Lets say you want to make it spin really fast and generate lots of wind for a long time - sounds like an awful lot of work doesn't it? Even just to make it spin faster and faster you need to do more work, right? And this is power, the rate at which work is performed. Replace you with an electric motor and it applies just the same.

    Resistors release heat and electric motors spin shafts - both forms of energy release can reflect power because they are performing work and at a certain rate.

    Cliff
     
  4. Oct 25, 2004 #3
    The rate at which work is done is power. The e.g. (moving a fan) given above. Electrical energy in short, can produce a mechanical force as u did to move a fan. The condition is that u must have a device on which work is to be done and it should be electricity compatible. :frown:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?