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I have been learning about voltage and I am still a bit confused.

A battery having 1.5 volt means that it has electrical potential energy difference of 1.5 volt right?

That means this potential to do work or energy is supplied when the battery is connected to the circuit and electrons flow as they recieve the energy?

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  • \$\begingroup\$ You're scrambling terminology here. There's only electric potential energy and potential difference (or voltage). There's no electrical potential energy difference. \$\endgroup\$
    – user103380
    Commented Aug 17, 2017 at 16:55
  • \$\begingroup\$ @KingDuken Well.. it is a potential energy difference of a charged particle. \$\endgroup\$
    – Eugene Sh.
    Commented Aug 17, 2017 at 16:56
  • \$\begingroup\$ @EugeneSh., the conceptual challenge for learners is (I think) that potential difference exists even when there's no particle there to have potential energy. \$\endgroup\$
    – The Photon
    Commented Aug 17, 2017 at 17:04
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    \$\begingroup\$ Both Olin's and the Photon's answers are correct. The Photon's is more fundamental, but Olin's is more accessible. Understand both if you can, and understand why they are equivalent. \$\endgroup\$
    – Neil_UK
    Commented Aug 17, 2017 at 17:19

2 Answers 2

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1.5 V is a measure of electrical potential. It is not energy, so electrical potential energy doesn't make sense.

One way to look at EMF is the potential of charge to do work. 3 Coulombs at a potential of 5 V can do 15 joules of work when flowing down to 0 potential. This is like a brick can do work while falling from a high spot (high gravitational potential) to a low spot (lower gravitational potential).

A battery is a pump for charge. As some charge flows from the higher to lower potential, the battery keeps replacing that charge at the high potential. This is like a pump moving water uphill so that you can run a water wheel from it. The water wheel is your circuit that is using power from the water to perform its function. The battery is the pump that takes the water from the bottom of the water wheel (at low potential) and moves it back up to the top (at high potential), where it can be used to run the water wheel again.

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  • \$\begingroup\$ thank you so much! I have to learn all these electrical stuff throught internet. So answers like these make such a great impact on my learning. (sorry for the bad english, it's not my native language) \$\endgroup\$
    – Farin 9848
    Commented Aug 18, 2017 at 15:51
  • \$\begingroup\$ @Farin9848 don't worry too much about your English. Good use of language is important but that will improve with use as will your understanding of electronics. Lots of people here don't have English as their first language. \$\endgroup\$ Commented Aug 19, 2017 at 16:35
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A battery having 1.5 volt means that it has electrical potential energy difference of 1.5 volt right?

There is a potential difference of 1.5 V.

This means that if you moved a +1 C test charge from one terminal to the other, you would need to do 1.5 J of work on the charge to move it from the negative terminal to the positive terminal. And this would add 1.5 J to the electrical potential energy of the test charge.

But the potential difference is defined even if there is no charge there to be moved or to have potential energy. Just like the electric field is there ready to apply a force to any charge that comes along, even when there's no charge actually there to have a force applied to it.

That means this potential to do work or energy is supplied when the battery is connected to the circuit and electrons flow as they recieve the energy?

When you connect the circuit, then the battery actually does work on charges to push them through the circuit. The "potential" or possibility to do work is there even before the circuit is connected.

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  • \$\begingroup\$ Are you sure you need only 1J to move 1C from 0V to 1.5V? \$\endgroup\$ Commented Aug 19, 2017 at 5:48

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