What is the difference of negative (-) and positive (+) in a battery?

Discussion in 'The Projects Forum' started by Lightfire, Dec 3, 2010.

  1. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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    What is the difference of negative (-) and positive (+) in a battery?

    Also, I found some wires colored black and red. Is those colors represents negative and positive? Does black means negative and red means positive?

    Also, what is the functionality of negative and positive? Where does the electricity flows? In negative or positive? Also if for example, it is in negative, what is the functionality of positive?
     
  2. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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  3. iONic

    AAC Fanatic!

    Nov 16, 2007
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    Essentially there is NO functionality unless you have both negative and positive, it's what they call "Potential Difference"

    It is fairly standard that the Red is Positive and the Black is negative.

    Electrons flow from the negative terminal to the positive terminal.

    Rfference:
    Voltage and Current
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
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    There are holes and electrons.

    The electrons leave a battery through the (-)negative terminal.

    When an electron shifts out, it leaves a hole.

    That hole, is a space where another electron can go.

    SO, When you connect a lightbulb through to a battery, the electrons leave the (-) terminal flow through the lightbulb some are converted to light, some to heat, and some make it back to the battery, filling some of the holes.

    Now, some of the electrons turned into light and heat, leaving the circuit.

    The color codes of wires are often made up by the designer.

    There are ACTUAL required colors used, but that changes state to state, country to country.

    Typically, black is (-) negative, red is (+)positive, green is EARTH ground.

    Earth ground connects to the case or chassis of a device, and leads back to a breaker box which connects it into a big spike into the ground.

    Here is a chapter in our eBook that explains current flow.

    It has diagrams so you can see how and where the current flows.

    http://www.allaboutcircuits.com/vol_1/chpt_1/7.html
     
  5. wayneh

    Expert

    Sep 9, 2010
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    An analogy is often made comparing electricity to water. Water or electrons at high potential (at the top of a waterfall, or at the "-" terminal of the battery) can be allowed to flow "downhill", giving up their stored "potential energy". Clever devices placed in the flow can convert this potential energy to different forms. A water turbine can generate electricity as the water passing thru it gives up its potential energy. A lightbulb can emit light energy and heat as electrons lose potential energy (voltage) passing thru it.

    A battery can't have just one pole, because it needs the other to provide the "downhill" part of the circuit, where the potential energy is lowest. Without a path to lower potential, the potential energy stored in a mountain lake or in a battery cannot be used.

    It's maybe worth noting that electrical current travels at the speed of light, however the electrons themselves move at human speeds, cm per sec. Metal is a conductor because its electron field allows electrons to move off one end as soon as other electrons enter the opposite end of the conductor. If we had to wait for the electrons themselves to pass thru a wire, the modern age wouldn't feel so modern.
     
  6. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
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    Honestly, I can't understand anything about it. Maybe because of my age? ;)
     
  7. steinar96

    Active Member

    Apr 18, 2009
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    It can take a while to get the hang of it. But in short it revolves around the electrons seeking the lowest energy state they can get to. The potential difference is a measure of how big the difference is between their current state and another. The bigger this difference is the more compelled they are to achieve this lower energy state. Resistance in materials prevents or slows down how fast a "group" of electrons seperated from a lower energy state manage to achieve this lower energy state. The 2 poles of a battery present areas which are at different potentials (energy states) when it comes to electrons. When you "complete the circuit" the electrons see a way to achieve lower energy states and start to flow according to ohms law governing the relationship between current, potential and resistance. The first thing you need to realise is that electricity is governed by relative or differential sizes. Not absolute ones.
     
  8. wayneh

    Expert

    Sep 9, 2010
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    There are few, but one, and perhaps the ONLY, advantage of growing older is that, if one stays curious, one acquires wisdom. Take the philosophy that you can learn anything you put your mind to, and you won't be disappointed.
     
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