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B Charge and electricity

  1. May 2, 2018 #1
    Hi guys i have a question i want an answer to let say i have an object that is negatively charged and another object positively charge and i connected them with a wires to a light bulb will they generate electricity and the object never lose their charge lets they they have unlimited charges.
  2. jcsd
  3. May 2, 2018 #2


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    The stored Electrical Energy will soon be dissipated in the light bulb. To keep the bulb alight, it is necessary to produce a continuous flow of charge from a Power Source.
  4. May 2, 2018 #3


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    Yes there will be an electrical current between the two objects, and if the conditions are right that current will be able to light the bulb.

    However, the the current is the charge from one object to the other, which reduces the charge at both objects (it doesn't matter whether you think in terms of positive charge moving to the negative charged object or negative charge moving to the positive charged object - either way the charge at both objects is reduced). Thus we must run out of charge and the current stops. Ther's no such thing as unlimited charge; it has to come from somewhere.

    A example of your setup would be an ordinary battery: the positive terminal is one object and the negative terminal is the other. There will be a current between them, but eventually the battery will be discharged and the current will stop.
  5. May 2, 2018 #4
    Thanks guys i got what i needed. I was confused by ac, dc and different electrical generators.

    I would also like to know if there are equation to calculate how much energy is generated if both object have a charge vaule of 1000 i guess feel free to correct me if iam wrong.
  6. May 2, 2018 #5


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    There is indeed such an equation (actually several of them, as the problem will be different depending on several things that you haven't specified) , but you'll need to know both the amount of charge, usually measured in Coulombs, and the voltage difference, usually measured in volts. Googling for "resistor power current" and "capacitor discharge" will get you started.... but it might be best to see if you can find an intro physics textbook that covers this material.
  7. May 8, 2018 #6
    ##E=\frac{C\cdot U^2}{2}##
  8. May 8, 2018 #7

    Mister T

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    That is essentially what you do when you hook a light bulb up to a battery, except the bulb will eventually stop glowing because the battery doesn't deliver an unlimited amount of charge. It eventually dies and has to be either replaced or recharged.
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