| , 1881 , part II, | Alternatively, it can also be defined as the W done by the an external force to bring it from the reference position r ref to some position r |
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| The reference zero is usually taken to be a state in which the individual point charges are very well separated "are at infinite separation" and are at rest | February 1853 ; and 2 W |
| Nonetheless, both definitions yield the same results | |
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