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What does this thing on batteries mean?

  1. Feb 14, 2016 #1
    Say that 6V battery is connected to a lamp that takes 3V from each coulomb. Does that mean that the battery can supply 6V or dependent upon the need of components in the circuit ?
  2. jcsd
  3. Feb 14, 2016 #2


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    What do you mean? "Take 3V from each coulomb" is totally meaningless.
  4. Feb 14, 2016 #3
    I mean 3 joules of energy from each coulomb.
  5. Feb 14, 2016 #4


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    It will supply 6V to any lamp connected across it since it is a 6V battery. Work done per unit charge is the potential difference, which is 6V here.
  6. Feb 14, 2016 #5


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    I will try to answer what I think you mean (not what you asked). The capacity of a battery is usually given in mAh (milliampère-hours) or Ah (ampère-hours). To translate this to coulombs, note that 1Ah = 3600 coulomb (or use http://www.rapidtables.com/convert/charge/ah-to-coulomb.htm).
  7. Feb 14, 2016 #6


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    Hi Sam. Is there any way you could clarify what you're asking using standard terminology? It sounds like you're referring to a lamp which has a voltage drop of 3 volts. Voltage drop is the loss of energy as current flows through a circuit. A voltage drop of 3 volts means that for every coulomb of charge that passes through the lamp, 3 joules of energy are "lost" to the lamp, leaving a remaining 3 joules/coulomb for the rest of the circuit.

    It means that while the battery is supplying 6 volts to the circuit as a whole, only half of that is being used by the lamp. The other 3 volts are being used elsewhere in the circuit.
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